Company lists · Data refreshed November 2026
Top 25 Mainframe and legacy system professional and managed services providers worldwide
RevenueBase identified 987 company matches for mainframe and legacy system professional and managed services providers worldwide as of November 2026 and tracks 34,034 professional contacts across them, including 9,867 with verified work emails. The United States is the largest market and London the largest hub.
This list covers company matches for mainframe and legacy system professional and managed services providers worldwide, found by RevenueBase SmartSearch using the meaning of business descriptions in its company graph at Exact. Ranked by professionals tracked, largest first. Rows show recorded descriptions where available, Exact search membership and the snapshot date. Data refreshed November 6, 2026. Country and city lists for mainframe and legacy system professional and managed services providers follow the table.
Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase SmartSearch, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.
The 25 largest mainframe and legacy system professional and managed services providers worldwide
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 8,318 contacts → | ||||
Exact match “Unleash Your Digital Workplace Potential with Compucom To be at the forefront of your industry, having the right technology is non-negotiable.” Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase | |||||
| 2 | 3,542 contacts → | ||||
Exact match “Ensono is an expert technology adviser and managed service provider.” Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase | |||||
| 3 | 2,153 contacts → | ||||
Exact match “TRT is a Global Provider of IT Server, Storage and Networking Services.” Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase | |||||
| 4 | 1,388 contacts → | ||||
Exact match “Kumaran Systems: Engineering Future-Ready Transformations Since 1992, Kumaran Systems has been helping enterprises bridge the past and the future, reimagining legacy systems and…” Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase | |||||
| 5 | 1,063 contacts → | ||||
Exact match “IBM i is evolving.” Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase | |||||
| 6 | 1,021 contacts → | ||||
Exact match Recorded description not available. Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase | |||||
| 7 | 1,000 contacts → | ||||
Exact match “IBA Group is one of the largest IT service providers in Eastern Europe, performing software development, migration, maintenance, support, and IT consulting services with IT and…” Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase | |||||
| 8 | 691 contacts → | ||||
Exact match “DecisionOne is the largest global independent technology support organization in the TPM and ISO markets.” Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase | |||||
| 9 | 534 contacts → | ||||
Exact match “At Ntiva, growing people (our employees, partners, and clients) is our mission.” Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase | |||||
| 10 | 456 contacts → | ||||
Exact match “TmaxSoft is a global software innovator focused on infrastructure and data modernization, with solutions that offer enterprise CIOs viable alternatives to support their global IT…” Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase | |||||
| 11 | 416 contacts → | ||||
Exact match “About Us 36+ Years of IT Infrastructure & Managed Services Expertise At Fourth Dimension Technologies (4DTech), we help organizations modernize, secure, and manage their IT…” Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase | |||||
| 12 | 365 contacts → | ||||
Exact match “Fresche Solutions is an AI-powered IT modernization company that manages and maximizes the value of your IBM i and Microsoft systems.” Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase | |||||
| 13 | 354 contacts → | ||||
Exact match “PruTech Solutions Inc.” Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase | |||||
| 14 | 351 contacts → | ||||
Exact match “VBT is a technology company which established by a dedicate group of experts and gives support in international area.” Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase | |||||
| 15 | 252 contacts → | ||||
Exact match “ONGC Systems provides businesses with comprehensive IT services, that automate and streamline operations, reduce risk and increase stability while lowering the cost of system…” Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase | |||||
| 16 | 239 contacts → | ||||
Exact match “Maintec Technologies offers globally compliant IT solutions that empower businesses to become more competitive by leveraging both onsite and offshore capabilities.” Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase | |||||
| 17 | 208 contacts → | ||||
Exact match “Astadia is the industry leader for mainframe migrations and modernizations.” Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase | |||||
| 18 | 189 contacts → | ||||
Exact match “People.” Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase | |||||
| 19 | 158 contacts → | ||||
Exact match “Logista Solutions is one of the largest Managed IT Service Providers in the United States.” Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase | |||||
| 20 | 136 contacts → | ||||
Exact match “VOTRE PARTENAIRE DE CONFIANCE POUR LES SOLUTIONS TECHNOLOGIQUES D’ENTREPRISE La transformation numérique est bien plus qu’un métier pour nous, c’est un engagement.” Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase | |||||
| 21 | 136 contacts → | ||||
Exact match “Our beliefs are simple: technology should power, not hinder.” Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase | |||||
| 22 | 125 contacts → | ||||
Exact match “Somos uma empresa especializada em soluções de tecnologia para serviços gerenciados com aderência às boas práticas, proporcionando às empresas uma gestão eficiente através de um…” Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase | |||||
| 23 | 125 contacts → | ||||
Exact match “MOST Software Technologies helps customers leverage their investment in mainframe applications.” Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase | |||||
| 24 | 118 contacts → | ||||
Exact match “FNTS has been a trusted, nationally recognized leader in managed IT services for more than 30 years.” Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase | |||||
| 25 | 111 contacts → | ||||
Exact match “Con más de 30 años de trayectoria, TDI LATAM es una compañía regional de servicios y soluciones tecnológicas especializada en mainframe, automatización, service ops, cloud…” Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase | |||||
RevenueBase SmartSearch
Describe a niche business in your own words. RevenueBase SmartSearch compares the meaning of your description with company business descriptions compiled in the RevenueBase company graph. Exact, Similar, Related and Broad control how closely companies must fit.
This list uses Exact for “mainframe and legacy system professional and managed services providers”. Each Exact match badge shows membership in that saved search; it is not an individual similarity score or a service-quality rating. Recorded descriptions are shown where available.
Showing 25 of 987 mainframe and legacy system professional and managed services providers worldwide
See the full list, filter by size, metro and specialty, and access 9,867 tracked professional contacts with verified work emails. Direct dials are available where recorded.
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Mainframe and legacy system professional and managed services providers worldwide at a glance
As of Nov 6, 2026Companies by employee count
Email recency is reported on each country list linked below.
How this list was built
The recorded descriptions help you assess these company matches. Check a company’s website for its current services and locations.
- Source
- The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase SmartSearch, the natural-language company search available to every RevenueBase user.
- Coverage
- Every country. Country and city lists for mainframe and legacy system professional and managed services providers are linked below.
- What qualifies
- Company records worldwide whose business descriptions match “mainframe and legacy system professional and managed services providers” by meaning at the Exact setting. Descriptions are compiled in the RevenueBase company graph from public websites, profiles and company information where available; they are not guaranteed quotations from the company's website.
- RevenueBase SmartSearch
- Describe a niche company in your own words to find businesses by meaning. Exact, Similar, Related and Broad control the breadth of RevenueBase SmartSearch. This saved list uses Exact. Each row's Exact match badge shows inclusion in that search, not an individual score or a service-quality judgment.
- Public preview
- The public preview omits records without a verified work email. Dataset totals and geographic summaries describe the full matched records before these preview filters.
- Match quality
- RevenueBase's August 25, 2026 study assessed 4,198 description/company pairs across matching settings. The publisher reports 86% good or better at Exact. This evaluates the method across queries; it does not audit this individual list. Recorded company descriptions, where available, help you judge each match yourself. Read the full methodology: how the lists are built and what the study measures.
- Ranking
- Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
- Verification
- Every displayed company carries at least one verified work email. RevenueBase tracks 9,867 professional contacts with verified work emails across the full matched dataset. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
- Refresh
- This page's figures were pulled from the company graph on November 6, 2026. Lists refresh periodically as the graph is re-checked.
- Record context
- Company records and descriptions can change. Check the company's website for its current services and locations.
Mainframe and legacy system professional and managed services providers by location
8 lists · largest firstEvery Mainframe and legacy system professional and managed services providers list RevenueBase publishes, by country and city. Counts are matching companies in each list as of its own refresh date.
Countries
- Mainframe and legacy system professional and managed services providers based in the United States321
- Mainframe and legacy system professional and managed services providers based in the United Kingdom66
- Mainframe and legacy system professional and managed services providers based in India53
- Mainframe and legacy system professional and managed services providers based in Germany50
- Mainframe and legacy system professional and managed services providers based in France42
- Mainframe and legacy system professional and managed services providers based in Australia40
- Mainframe and legacy system professional and managed services providers based in Canada32
- Mainframe and legacy system professional and managed services providers based in Italy31
Frequently asked
What is RevenueBase SmartSearch?
RevenueBase SmartSearch finds niche companies by the meaning of their business descriptions in the RevenueBase company graph. Exact, Similar, Related and Broad control how closely companies must fit your description. This list uses Exact for “mainframe and legacy system professional and managed services providers”; each Exact match badge shows search membership, not an individual similarity or quality score.
How many mainframe and legacy system professional and managed services providers are there worldwide?
RevenueBase identified 987 company matches for mainframe and legacy system professional and managed services providers worldwide as of November 2026, using the meaning of business descriptions at Exact. This is the recorded matched set in the RevenueBase company graph.
What is the largest company on this list?
Compucom tops the displayed preview by professional contacts tracked in RevenueBase. Recorded headquarters appear in the company rows.
Which country has the most mainframe and legacy system professional and managed services providers?
The United States leads with 321 companies, followed by the United Kingdom (66) and India (53). Every mainframe and legacy system professional and managed services providers list by country and city is linked on this page.
Which city has the most mainframe and legacy system professional and managed services providers?
London leads with 14 company records, followed by New York (12) and Bangalore (9).
How do I get contact information for these companies?
A free RevenueBase account lets you run this exact search and work limited free results with 500 credits to start. Upgrading provides access to the 9,867 professional contacts with verified work emails tracked across these 987 companies; direct dials are available where recorded.
How current is this list?
The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on November 6, 2026.
Ready to reach these companies? Verified emails and direct dials for all 987 mainframe and legacy system professional and managed services providers worldwide. Start with a free account, no credit card.
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About this data
RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase SmartSearch, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.
More company lists
Company intelligence · public preview
Top 25 mainframe and legacy system professional and managed services providers worldwide
Find companies in any niche.
Describe the businesses you want in your own words. RevenueBase SmartSearch matches company descriptions by meaning.
RevenueBase records 987 matching company records for mainframe and legacy system professional and managed services providers worldwide, with 34,034 tracked contacts and 9,867 verified work emails.
This public preview shows 25 selected records ordered by tracked contacts. RevenueBase SmartSearch finds company descriptions that match by meaning at Exact. Snapshot: November 6, 2026.
RevenueBase compiles business descriptions for niche-company discovery; each row shows a recorded excerpt where available. Adapt this search to find the companies and contacts you want.
Top 25 mainframe and legacy system professional and managed services providers worldwide
The public list shows selected company records with contact and verified-email coverage. Reported employee bands provide separate company-size context.
| # | Company | Headquarters on record | Reported employees | RevenueBase SmartSearch | Tracked contacts |
|---|---|---|---|---|---|
| 1 |  Compucomcompucom.comHQ: Fort Mill, WA, United StatesReported employees: 5,001-10,000 | Fort Mill, WA, United States | 5,001-10,000 | Exact match | 8,318 contacts → |
“Unleash Your Digital Workplace Potential with Compucom To be at the forefront of your industry, having the right technology is non-negotiable.” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 2 |  Ensonoensono.comHQ: Downers Grove, IL, United StatesReported employees: 1,001-5,000 | Downers Grove, IL, United States | 1,001-5,000 | Exact match | 3,542 contacts → |
“Ensono is an expert technology adviser and managed service provider.” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 3 |  TRTtrt.comHQ: Singapore, GermanyReported employees: Not recorded | Singapore, Germany | Not recorded | Exact match | 2,153 contacts → |
“TRT is a Global Provider of IT Server, Storage and Networking Services.” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 4 |  Kumaran Systemskumaran.comHQ: Chennai, CA, IndiaReported employees: 1,001-5,000 | Chennai, CA, India | 1,001-5,000 | Exact match | 1,388 contacts → |
“Kumaran Systems: Engineering Future-Ready Transformations Since 1992, Kumaran Systems has been helping enterprises bridge the past and the future, reimagining legacy systems and…” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 5 |  programmers.ioprogrammers.ioHQ: Dallas, TX, United StatesReported employees: 1,001-5,000 | Dallas, TX, United States | 1,001-5,000 | Exact match | 1,063 contacts → |
“IBM i is evolving.” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 6 |  Kyndryl Japankyndryl.comHQ: United StatesReported employees: 1,001-5,000 | United States | 1,001-5,000 | Exact match | 1,021 contacts → |
No recorded description excerpt is available for this public record. | |||||
| 7 |  IBA Groupibagroupit.comHQ: Prague, CA, Czech RepublicReported employees: 1,001-5,000 | Prague, CA, Czech Republic | 1,001-5,000 | Exact match | 1,000 contacts → |
“IBA Group is one of the largest IT service providers in Eastern Europe, performing software development, migration, maintenance, support, and IT consulting services with IT and…” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 8 |  Decisiononedecisionone.comHQ: Havertown, PA, United StatesReported employees: 501-1,000 | Havertown, PA, United States | 501-1,000 | Exact match | 691 contacts → |
“DecisionOne is the largest global independent technology support organization in the TPM and ISO markets.” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 9 |  Ntiva, INCntiva.comHQ: Mclean, VA, United StatesReported employees: 501-1,000 | Mclean, VA, United States | 501-1,000 | Exact match | 534 contacts → |
“At Ntiva, growing people (our employees, partners, and clients) is our mission.” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 10 |  Tmaxsofttmaxsoft.comHQ: Gyeonggi-do, South KoreaReported employees: 501-1,000 | Gyeonggi-do, South Korea | 501-1,000 | Exact match | 456 contacts → |
“TmaxSoft is a global software innovator focused on infrastructure and data modernization, with solutions that offer enterprise CIOs viable alternatives to support their global IT…” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 11 |  Fourth Dimension Technologiesfourdtech.comHQ: Chennai, CA, IndiaReported employees: 501-1,000 | Chennai, CA, India | 501-1,000 | Exact match | 416 contacts → |
“About Us 36+ Years of IT Infrastructure & Managed Services Expertise At Fourth Dimension Technologies (4DTech), we help organizations modernize, secure, and manage their IT…” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 12 |  Fresche Solutionsfreschesolutions.comHQ: Montréal, QC, CanadaReported employees: 201-500 | Montréal, QC, Canada | 201-500 | Exact match | 365 contacts → |
“Fresche Solutions is an AI-powered IT modernization company that manages and maximizes the value of your IBM i and Microsoft systems.” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 13 |  Prutech Solutions, INCprutech.comHQ: Iselin, United StatesReported employees: 501-1,000 | Iselin, United States | 501-1,000 | Exact match | 354 contacts → |
“PruTech Solutions Inc.” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 14 |  VBT Softwarevbt.com.trHQ: Atasehir, TürkiyeReported employees: 201-500 | Atasehir, Türkiye | 201-500 | Exact match | 351 contacts → |
“VBT is a technology company which established by a dedicate group of experts and gives support in international area.” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 15 |  Ongc Systemsongc.com.auHQ: Arundel, AustraliaReported employees: Not recorded | Arundel, Australia | Not recorded | Exact match | 252 contacts → |
“ONGC Systems provides businesses with comprehensive IT services, that automate and streamline operations, reduce risk and increase stability while lowering the cost of system…” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 16 |  Maintec Technologies - USAmaintec.comHQ: Raleigh, United StatesReported employees: 501-1,000 | Raleigh, United States | 501-1,000 | Exact match | 239 contacts → |
“Maintec Technologies offers globally compliant IT solutions that empower businesses to become more competitive by leveraging both onsite and offshore capabilities.” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 17 |  Astadiaastadia.comHQ: St. Louis, MO, United StatesReported employees: 201-500 | St. Louis, MO, United States | 201-500 | Exact match | 208 contacts → |
“Astadia is the industry leader for mainframe migrations and modernizations.” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 18 |  Alpha Technologies INCalphait.usHQ: Wilmington, United StatesReported employees: 201-500 | Wilmington, United States | 201-500 | Exact match | 189 contacts → |
“People.” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 19 |  Logista Solutionslogistasolutions.comHQ: Bessemer, MS, United StatesReported employees: 201-500 | Bessemer, MS, United States | 201-500 | Exact match | 158 contacts → |
“Logista Solutions is one of the largest Managed IT Service Providers in the United States.” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 20 |  MSP Corpmspcorp.caHQ: Montreal, QC, CanadaReported employees: 501-1,000 | Montreal, QC, Canada | 501-1,000 | Exact match | 136 contacts → |
“VOTRE PARTENAIRE DE CONFIANCE POUR LES SOLUTIONS TECHNOLOGIQUES D’ENTREPRISE La transformation numérique est bien plus qu’un métier pour nous, c’est un engagement.” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 21 |  FAR OUT Solutionsfaroutsolutions.comHQ: Winter Park, FL, United StatesReported employees: 201-500 | Winter Park, FL, United States | 201-500 | Exact match | 136 contacts → |
“Our beliefs are simple: technology should power, not hinder.” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 22 |  Proative Technologyproativetec.com.brHQ: Alphaville, BrazilReported employees: 51-200 | Alphaville, Brazil | 51-200 | Exact match | 125 contacts → |
“Somos uma empresa especializada em soluções de tecnologia para serviços gerenciados com aderência às boas práticas, proporcionando às empresas uma gestão eficiente através de um…” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 23 |  Most Technologiesmosttechnologies.comHQ: Atlanta, GA, IsraelReported employees: 51-200 | Atlanta, GA, Israel | 51-200 | Exact match | 125 contacts → |
“MOST Software Technologies helps customers leverage their investment in mainframe applications.” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 24 |  FNTSfnts.comHQ: Omaha, NE, United StatesReported employees: 51-200 | Omaha, NE, United States | 51-200 | Exact match | 118 contacts → |
“FNTS has been a trusted, nationally recognized leader in managed IT services for more than 30 years.” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 25 |  TDI Latamtdilatam.comHQ: Buenos Aires, ArgentinaReported employees: 201-500 | Buenos Aires, Argentina | 201-500 | Exact match | 111 contacts → |
“Con más de 30 años de trayectoria, TDI LATAM es una compañía regional de servicios y soluciones tecnológicas especializada en mainframe, automatización, service ops, cloud…” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
Showing 25 of 987 company matches
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Mainframe and legacy system professional and managed services providers: dataset insights
November 6, 2026These summaries describe recorded coverage in this saved dataset. This page is derived from saved source records; per-contact mobile coverage and email-recency results are not established by this snapshot.
Reported company sizes
983 records in the displayed employee bands.
4 matching records are outside the displayed bands or do not have a displayed size. Bars show shares of the displayed bands.
Email recency for this list is measured across the whole country list rather than for Worldwide, so it is reported there. Company counts and contact totals on this page are exact for Worldwide, over 987 companies.
How this company list was built
Describe a niche in your own words: companies installing commercial solar, or manufacturers of sustainable packaging. RevenueBase SmartSearch finds companies whose compiled business descriptions match by meaning. This list is one saved example to adapt.
Where the company descriptions come from
RevenueBase compiles company information from public sources, including company websites and public professional profiles such as LinkedIn, alongside information supplied by companies. The short recorded excerpt shown here is separate from the complete business description used for matching; individual source URLs and collection dates are not provided in this public snapshot.
RevenueBase SmartSearch matching settings
- Exact
- Closest fits to the business described.
- Similar
- Similar businesses with a wider range of fits.
- Related
- Related businesses in and around the category.
- Broad
- A broader set of businesses connected to the description.
RevenueBase SmartSearch · Exact match identifies inclusion in this search's closest semantic matching setting. It is not a per-company confidence score, a literal keyword match, or a quality endorsement.
Selection, ordering and scope
The public list shows selected company records with contact and verified-email coverage. Reported employee bands provide separate company-size context.
This page is derived from saved source records; per-contact mobile coverage and email-recency results are not established by this snapshot.
Recorded company descriptions support research; check company websites for current services. The selected preview is ordered by tracked contacts and is not a list of the best service providers.
Snapshot: November 6, 2026.
RevenueBase is a B2B data infrastructure company. Its September 3, 2026 published methodology describes a graph of 60 million companies and 398.9 million professional contacts; these platform figures differ from this page's totals. Published methodology ↗
Mainframe and legacy system professional and managed services providers by location
8 lists · largest firstEvery Mainframe and legacy system professional and managed services providers list RevenueBase publishes, by country and city. Counts are matching companies in each list as of its own refresh date.
Countries
- Mainframe and legacy system professional and managed services providers based in the United States321
- Mainframe and legacy system professional and managed services providers based in the United Kingdom66
- Mainframe and legacy system professional and managed services providers based in India53
- Mainframe and legacy system professional and managed services providers based in Germany50
- Mainframe and legacy system professional and managed services providers based in France42
- Mainframe and legacy system professional and managed services providers based in Australia40
- Mainframe and legacy system professional and managed services providers based in Canada32
- Mainframe and legacy system professional and managed services providers based in Italy31
Questions about this company list
What does Exact match mean for mainframe and legacy system professional and managed services providers?
The separate RevenueBase SmartSearch column identifies inclusion at the closest semantic matching preset. It is not a literal keyword match, a per-company confidence score or a quality endorsement. Changing the search form opens a new search in RevenueBase; it does not reclassify these saved rows.
How many mainframe and legacy system professional and managed services providers did RevenueBase find worldwide?
The saved snapshot records 987 matching company records, 34,034 tracked contacts and 9,867 verified emails. The public preview displays 25 selected records.
Where do the company descriptions come from?
RevenueBase compiles company information from public sources, including company websites and public professional profiles such as LinkedIn, alongside information supplied by companies. The short recorded excerpt shown here is separate from the complete business description used for matching; individual source URLs and collection dates are not provided in this public snapshot.
How are the public companies ordered?
The selected public records are ordered by contacts tracked in RevenueBase, highest first. Contact coverage is a prospecting measure, not an assessment of the company's services or quality.
How can I get contact information?
Select a company's contact count to open its filtered contacts in RevenueBase. Free signup is required and includes 500 credits and limited free results. Verified emails, direct dials and mobile numbers depend on available coverage.
How current is this list?
Snapshot: November 6, 2026. Review each company's website for current services and locations. A recorded business description does not establish that every company offers every service named in the search.
What do headquarters and employee bands mean?
These are recorded company-level fields, rather than a map of every branch or a count of specialists. Missing headquarters or employee bands are labeled; older records may show a location separately from recorded headquarters.
Build your next target company list
Adapt this niche search and work with available contacts in RevenueBase.
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Cite this list
RevenueBase Data Team. Top 25 mainframe and legacy system professional and managed services providers worldwide. Snapshot: November 6, 2026. https://revenuebase.ai/companies/browse/mainframe-and-legacy-system-professional-and-managed-services-providers.
This is a selected public preview of saved company records, rather than an independently verified census. Open the source page ↗
More company lists
Company intelligence · public preview
Top 25 mainframe and legacy system professional and managed services providers worldwide
RevenueBase records 987 matching company records for mainframe and legacy system professional and managed services providers worldwide, with 34,034 tracked contacts and 9,867 verified work emails.
This public preview shows 25 selected records ordered by tracked contacts. RevenueBase SmartSearch finds company descriptions that match by meaning at Exact. Snapshot: November 6, 2026.
RevenueBase compiles business descriptions for niche-company discovery; each row shows a recorded excerpt where available. Adapt this search to find the companies and contacts you want.
Top 25 mainframe and legacy system professional and managed services providers worldwide
The public list shows selected company records with contact and verified-email coverage. Reported employee bands provide separate company-size context.
| # | Company | Headquarters on record | Reported employees | RevenueBase SmartSearch | Tracked contacts |
|---|---|---|---|---|---|
| 1 | Compucomcompucom.com HQ: Fort Mill, WA, United StatesReported employees: 5,001-10,000 | Fort Mill, WA, United States | 5,001-10,000 | Exact match | 8,318 contacts → |
“Unleash Your Digital Workplace Potential with Compucom To be at the forefront of your industry, having the right technology is non-negotiable.” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 2 | Ensonoensono.com HQ: Downers Grove, IL, United StatesReported employees: 1,001-5,000 | Downers Grove, IL, United States | 1,001-5,000 | Exact match | 3,542 contacts → |
“Ensono is an expert technology adviser and managed service provider.” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 3 | TRTtrt.com HQ: Singapore, GermanyReported employees: Not recorded | Singapore, Germany | Not recorded | Exact match | 2,153 contacts → |
“TRT is a Global Provider of IT Server, Storage and Networking Services.” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 4 | Kumaran Systemskumaran.com HQ: Chennai, CA, IndiaReported employees: 1,001-5,000 | Chennai, CA, India | 1,001-5,000 | Exact match | 1,388 contacts → |
“Kumaran Systems: Engineering Future-Ready Transformations Since 1992, Kumaran Systems has been helping enterprises bridge the past and the future, reimagining legacy systems and…” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 5 | programmers.ioprogrammers.io HQ: Dallas, TX, United StatesReported employees: 1,001-5,000 | Dallas, TX, United States | 1,001-5,000 | Exact match | 1,063 contacts → |
“IBM i is evolving.” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 6 | Kyndryl Japankyndryl.com HQ: United StatesReported employees: 1,001-5,000 | United States | 1,001-5,000 | Exact match | 1,021 contacts → |
No recorded description excerpt is available for this public record. | |||||
| 7 | IBA Groupibagroupit.com HQ: Prague, CA, Czech RepublicReported employees: 1,001-5,000 | Prague, CA, Czech Republic | 1,001-5,000 | Exact match | 1,000 contacts → |
“IBA Group is one of the largest IT service providers in Eastern Europe, performing software development, migration, maintenance, support, and IT consulting services with IT and…” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 8 | Decisiononedecisionone.com HQ: Havertown, PA, United StatesReported employees: 501-1,000 | Havertown, PA, United States | 501-1,000 | Exact match | 691 contacts → |
“DecisionOne is the largest global independent technology support organization in the TPM and ISO markets.” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 9 | Ntiva, INCntiva.com HQ: Mclean, VA, United StatesReported employees: 501-1,000 | Mclean, VA, United States | 501-1,000 | Exact match | 534 contacts → |
“At Ntiva, growing people (our employees, partners, and clients) is our mission.” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 10 | Tmaxsofttmaxsoft.com HQ: Gyeonggi-do, South KoreaReported employees: 501-1,000 | Gyeonggi-do, South Korea | 501-1,000 | Exact match | 456 contacts → |
“TmaxSoft is a global software innovator focused on infrastructure and data modernization, with solutions that offer enterprise CIOs viable alternatives to support their global IT…” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 11 | Fourth Dimension Technologiesfourdtech.com HQ: Chennai, CA, IndiaReported employees: 501-1,000 | Chennai, CA, India | 501-1,000 | Exact match | 416 contacts → |
“About Us 36+ Years of IT Infrastructure & Managed Services Expertise At Fourth Dimension Technologies (4DTech), we help organizations modernize, secure, and manage their IT…” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 12 | Fresche Solutionsfreschesolutions.com HQ: Montréal, QC, CanadaReported employees: 201-500 | Montréal, QC, Canada | 201-500 | Exact match | 365 contacts → |
“Fresche Solutions is an AI-powered IT modernization company that manages and maximizes the value of your IBM i and Microsoft systems.” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 13 | Prutech Solutions, INCprutech.com HQ: Iselin, United StatesReported employees: 501-1,000 | Iselin, United States | 501-1,000 | Exact match | 354 contacts → |
“PruTech Solutions Inc.” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 14 | VBT Softwarevbt.com.tr HQ: Atasehir, TürkiyeReported employees: 201-500 | Atasehir, Türkiye | 201-500 | Exact match | 351 contacts → |
“VBT is a technology company which established by a dedicate group of experts and gives support in international area.” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 15 | Ongc Systemsongc.com.au HQ: Arundel, AustraliaReported employees: Not recorded | Arundel, Australia | Not recorded | Exact match | 252 contacts → |
“ONGC Systems provides businesses with comprehensive IT services, that automate and streamline operations, reduce risk and increase stability while lowering the cost of system…” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 16 | Maintec Technologies - USAmaintec.com HQ: Raleigh, United StatesReported employees: 501-1,000 | Raleigh, United States | 501-1,000 | Exact match | 239 contacts → |
“Maintec Technologies offers globally compliant IT solutions that empower businesses to become more competitive by leveraging both onsite and offshore capabilities.” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 17 | Astadiaastadia.com HQ: St. Louis, MO, United StatesReported employees: 201-500 | St. Louis, MO, United States | 201-500 | Exact match | 208 contacts → |
“Astadia is the industry leader for mainframe migrations and modernizations.” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 18 | Alpha Technologies INCalphait.us HQ: Wilmington, United StatesReported employees: 201-500 | Wilmington, United States | 201-500 | Exact match | 189 contacts → |
“People.” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 19 | Logista Solutionslogistasolutions.com HQ: Bessemer, MS, United StatesReported employees: 201-500 | Bessemer, MS, United States | 201-500 | Exact match | 158 contacts → |
“Logista Solutions is one of the largest Managed IT Service Providers in the United States.” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 20 | MSP Corpmspcorp.ca HQ: Montreal, QC, CanadaReported employees: 501-1,000 | Montreal, QC, Canada | 501-1,000 | Exact match | 136 contacts → |
“VOTRE PARTENAIRE DE CONFIANCE POUR LES SOLUTIONS TECHNOLOGIQUES D’ENTREPRISE La transformation numérique est bien plus qu’un métier pour nous, c’est un engagement.” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 21 | FAR OUT Solutionsfaroutsolutions.com HQ: Winter Park, FL, United StatesReported employees: 201-500 | Winter Park, FL, United States | 201-500 | Exact match | 136 contacts → |
“Our beliefs are simple: technology should power, not hinder.” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 22 | Proative Technologyproativetec.com.br HQ: Alphaville, BrazilReported employees: 51-200 | Alphaville, Brazil | 51-200 | Exact match | 125 contacts → |
“Somos uma empresa especializada em soluções de tecnologia para serviços gerenciados com aderência às boas práticas, proporcionando às empresas uma gestão eficiente através de um…” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 23 | Most Technologiesmosttechnologies.com HQ: Atlanta, GA, IsraelReported employees: 51-200 | Atlanta, GA, Israel | 51-200 | Exact match | 125 contacts → |
“MOST Software Technologies helps customers leverage their investment in mainframe applications.” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 24 | FNTSfnts.com HQ: Omaha, NE, United StatesReported employees: 51-200 | Omaha, NE, United States | 51-200 | Exact match | 118 contacts → |
“FNTS has been a trusted, nationally recognized leader in managed IT services for more than 30 years.” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 25 | TDI Latamtdilatam.com HQ: Buenos Aires, ArgentinaReported employees: 201-500 | Buenos Aires, Argentina | 201-500 | Exact match | 111 contacts → |
“Con más de 30 años de trayectoria, TDI LATAM es una compañía regional de servicios y soluciones tecnológicas especializada en mainframe, automatización, service ops, cloud…” Recorded description excerpt · November 6, 2026Open company data in RevenueBase ↗Free signup required. | |||||
Showing 25 of 987 company matches
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Mainframe and legacy system professional and managed services providers: dataset insights
November 6, 2026These summaries describe recorded coverage in this saved dataset. This page is derived from saved source records; per-contact mobile coverage and email-recency results are not established by this snapshot.
Reported company sizes
983 records in the displayed employee bands.
4 matching records are outside the displayed bands or do not have a displayed size. Bars show shares of the displayed bands.
Email recency for this list is measured across the whole country list rather than for Worldwide, so it is reported there. Company counts and contact totals on this page are exact for Worldwide, over 987 companies.
How this company list was built
Describe a niche in your own words: companies installing commercial solar, or manufacturers of sustainable packaging. RevenueBase SmartSearch finds companies whose compiled business descriptions match by meaning. This list is one saved example to adapt.
Where the company descriptions come from
RevenueBase compiles company information from public sources, including company websites and public professional profiles such as LinkedIn, alongside information supplied by companies. The short recorded excerpt shown here is separate from the complete business description used for matching; individual source URLs and collection dates are not provided in this public snapshot.
RevenueBase SmartSearch matching settings
- Exact
- Closest fits to the business described.
- Similar
- Similar businesses with a wider range of fits.
- Related
- Related businesses in and around the category.
- Broad
- A broader set of businesses connected to the description.
RevenueBase SmartSearch · Exact match identifies inclusion in this search's closest semantic matching setting. It is not a per-company confidence score, a literal keyword match, or a quality endorsement.
Selection, ordering and scope
The public list shows selected company records with contact and verified-email coverage. Reported employee bands provide separate company-size context.
This page is derived from saved source records; per-contact mobile coverage and email-recency results are not established by this snapshot.
Recorded company descriptions support research; check company websites for current services. The selected preview is ordered by tracked contacts and is not a list of the best service providers.
Snapshot: November 6, 2026.
RevenueBase is a B2B data infrastructure company. Its September 3, 2026 published methodology describes a graph of 60 million companies and 398.9 million professional contacts; these platform figures differ from this page's totals. Published methodology ↗
Mainframe and legacy system professional and managed services providers by location
8 lists · largest firstEvery Mainframe and legacy system professional and managed services providers list RevenueBase publishes, by country and city. Counts are matching companies in each list as of its own refresh date.
Countries
- Mainframe and legacy system professional and managed services providers based in the United States321
- Mainframe and legacy system professional and managed services providers based in the United Kingdom66
- Mainframe and legacy system professional and managed services providers based in India53
- Mainframe and legacy system professional and managed services providers based in Germany50
- Mainframe and legacy system professional and managed services providers based in France42
- Mainframe and legacy system professional and managed services providers based in Australia40
- Mainframe and legacy system professional and managed services providers based in Canada32
- Mainframe and legacy system professional and managed services providers based in Italy31
Questions about this company list
What does Exact match mean for mainframe and legacy system professional and managed services providers?
The separate RevenueBase SmartSearch column identifies inclusion at the closest semantic matching preset. It is not a literal keyword match, a per-company confidence score or a quality endorsement. Changing the search form opens a new search in RevenueBase; it does not reclassify these saved rows.
How many mainframe and legacy system professional and managed services providers did RevenueBase find worldwide?
The saved snapshot records 987 matching company records, 34,034 tracked contacts and 9,867 verified emails. The public preview displays 25 selected records.
Where do the company descriptions come from?
RevenueBase compiles company information from public sources, including company websites and public professional profiles such as LinkedIn, alongside information supplied by companies. The short recorded excerpt shown here is separate from the complete business description used for matching; individual source URLs and collection dates are not provided in this public snapshot.
How are the public companies ordered?
The selected public records are ordered by contacts tracked in RevenueBase, highest first. Contact coverage is a prospecting measure, not an assessment of the company's services or quality.
How can I get contact information?
Select a company's contact count to open its filtered contacts in RevenueBase. Free signup is required and includes 500 credits and limited free results. Verified emails, direct dials and mobile numbers depend on available coverage.
How current is this list?
Snapshot: November 6, 2026. Review each company's website for current services and locations. A recorded business description does not establish that every company offers every service named in the search.
What do headquarters and employee bands mean?
These are recorded company-level fields, rather than a map of every branch or a count of specialists. Missing headquarters or employee bands are labeled; older records may show a location separately from recorded headquarters.
Build your next target company list
Adapt this niche search and work with available contacts in RevenueBase.
Related lists
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Cite this list
RevenueBase Data Team. Top 25 mainframe and legacy system professional and managed services providers worldwide. Snapshot: November 6, 2026. https://revenuebase.ai/companies/browse/mainframe-and-legacy-system-professional-and-managed-services-providers.
This is a selected public preview of saved company records, rather than an independently verified census. Open the source page ↗