Company lists · Data refreshed November 2026

Top 25 Open source developers worldwide

RevenueBase identified 281 company matches for open source developers worldwide as of November 2026 and tracks 5,025 professional contacts across them, including 417 with verified work emails. The United States is the largest market and Berlin the largest hub.

This list covers company matches for open source developers 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 open source developers 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.

How to read this list RevenueBase SmartSearch · Exact Recorded Nov 6, 2026 How this list was built
281Companies
5,025Contacts tracked
417Verified emails
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The 25 largest open source developers worldwide

Ranked by team size
Top 25 of 281 company matches for open source developers worldwide, ordered by professional contacts tracked in RevenueBase, largest first. Recorded Nov 6, 2026. The RevenueBase SmartSearch column shows Exact match membership in this saved search. Click a contact count to view that company's people. Totals use company locations recorded by RevenueBase; the displayed preview is a smaller selection.
#CompanyRevenueBase SmartSearchHeadquartersEmployeesContacts
1Exact matchWilmington, DE, United StatesHQ recorded Nov 6, 20265,001-10,0001,207 contacts →

Exact match

“The Apache Software Foundation (ASF) is the global home for open source software, powering some of the world’s most ubiquitous software projects including Apache Airflow, Apache…”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
2Exact matchSan Francisco, CA, United StatesHQ recorded Nov 6, 2026201-500866 contacts →

Exact match

“The Linux Foundation is the organization of choice for the world's top developers and companies to build ecosystems that accelerate open technology development and commercial…”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
3Exact matchNoida, IndiaHQ recorded Nov 6, 2026501-1,000666 contacts →

Exact match

“Webkul is one of the largest self-created open-source marketplaces in the world.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
4Exact matchIssy-les-moulineaux, FranceHQ recorded Nov 6, 2026201-500149 contacts →

Exact match

“Notre Mission est depuis 20 ans, d’inventer et de développer les Logiciels Libres et Open Source éthiques (ce que nous appelons la « GoodTech ») pour participer à changer le Monde…”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
5Exact matchMumbai, IndiaHQ recorded Nov 6, 202651-200123 contacts →

Exact match

“Frappe creates 100% open source software to help businesses grow sustainably.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
6Exact matchİstanbul, TürkiyeHQ recorded Nov 6, 202611-5041 contacts →

Exact match

“Ozgur Software Inc.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
7Exact matchSingaporeHQ recorded Nov 6, 2026501-1,00037 contacts →

Exact match

“FOSSASIA develops Open Source software and hardware solutions with a global developer community from its base in Asia and organizes Open Technology events around the year.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
8Exact matchCanberra, AustraliaHQ recorded Nov 6, 202611-5037 contacts →

Exact match

“We are a not-for-profit organization focused on open source software development, innovation and education.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
9Exact matchKathmandu, NepalHQ recorded Nov 6, 202651-20017 contacts →

Exact match

“Eydean builds the most powerful and flexible tools for modern businesses.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
10Exact matchParis, FranceHQ recorded Nov 6, 202611-5013 contacts →

Exact match

“Spécialistes du développement Open Source (PHP, Javascript) Cloud et OPS / Associé Time For The Planet et certifié Great Place To Work”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
11Exact matchSomerville, MA, United StatesHQ recorded Nov 6, 20261-1011 contacts →

Exact match

“Unison Computing is a Delaware public benefit corp.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
12Exact matchKiel, GermanyHQ recorded Nov 6, 202611-5011 contacts →

Exact match

“ECC Digital baut Open-Source-Software, die nach dem Projekt nicht im Regal landet.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
13Exact matchWixom, MI, United StatesHQ recorded Nov 6, 20261-1011 contacts →

Exact match

“Nonadyne Inc was founded in 2013.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
14Exact matchKolkata, IndiaHQ recorded Nov 6, 20261-109 contacts →

Exact match

“Our business philosophy is based upon getting the best out of free and open source software.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
15Exact matchModena, ItalyHQ recorded Nov 6, 20261-108 contacts →

Exact match

“PyTech nasce nel 2021 dalla partnership di tre programmatori con la passione per il mondo del software libero e un imprenditore proveniente dal mondo delle energie rinnovabili.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
16Exact matchStuttgart, GermanyHQ recorded Nov 6, 20261-107 contacts →

Exact match

“Our Open-Source is part of our company.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
17Exact matchTallinn, EstoniaHQ recorded Nov 6, 20261-107 contacts →

Exact match

“Kendraio is an independent nonprofit research project, building free open-source software.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
18Exact matchSan Giuliano Terme, ItalyHQ recorded Nov 6, 20261-106 contacts →

Exact match

“Sviluppo di soluzioni basate su Software Open Source che meglio si adattano alle varie esigenze; per non rimanere ad fermo ad aspettare.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
19Exact matchAustin, United StatesHQ recorded Nov 6, 202611-506 contacts →

Exact match

“Free open source code you can run and adapt.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
20Exact matchNew York, NY, United StatesHQ recorded Nov 6, 20261-106 contacts →

Exact match

“Software in the Public Interest is a non-profit organization which was founded to help organizations develop and distribute open hardware and software.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
21Exact matchProvidence, RI, United StatesHQ recorded Nov 6, 20261-106 contacts →

Exact match

“Hello world!”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
22Exact matchVaraždin, CroatiaHQ recorded Nov 6, 20261-104 contacts →

Exact match

“Vjerujemo da najnovije tehnologije moraju biti dostupne svima.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
23Exact matchThailandHQ recorded Nov 6, 202611-504 contacts →

Exact match

“Our Mission 1.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
24Exact matchUnited StatesHQ recorded Nov 6, 20261-104 contacts →

Exact match

“The OBS Project is a worldwide community of developers, support volunteers and other contributors with the shared goal of creating free, open-source tools for everyone.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
25Exact matchUnited StatesHQ recorded Nov 6, 20261-104 contacts →

Exact match

“For a sustainable and healthy open source ecosystem”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase

Showing 25 of 281 open source developers worldwide

See the full list, filter by size, metro and specialty, and access 417 tracked professional contacts with verified work emails. Direct dials are available where recorded.

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Open source developers worldwide at a glance

As of Nov 6, 2026
8.3%Verified-email coverage
17.9Average contacts per company
1-10Median size (employees)
1.8%Largest-city concentration · Berlin
Nov 6, 2026Page data refreshed

Companies by employee count

1-10
200
11-50
52
51-200
15
201-500
3
501-1,000
4
1,001-5,000
2
5,001-10,000
1
10001+
3

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 open source developers are linked below.
What qualifies
Company records worldwide whose business descriptions match “open source developers” 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 417 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.

Open source developers by location

1 lists · largest first

Every Open source developers list RevenueBase publishes, by country and city. Counts are matching companies in each list as of its own refresh date.

Countries

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 “open source developers”; each Exact match badge shows search membership, not an individual similarity or quality score.

How many open source developers are there worldwide?

RevenueBase identified 281 company matches for open source developers 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?

The Apache Software Foundation tops the displayed preview by professional contacts tracked in RevenueBase. Recorded headquarters appear in the company rows.

Which country has the most open source developers?

The United States leads with 48 companies. Every open source developers list by country and city is linked on this page.

Which city has the most open source developers?

Berlin leads with 5 company records, followed by Los Angeles (4) and New York (4).

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 417 professional contacts with verified work emails tracked across these 281 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.

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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.