Company lists · Data refreshed September 2026
Top 21 Open source software companies based in the United States
RevenueBase identified 101 open source software companies headquartered in the United States as of September 2026 and tracks 28,460 professional contacts across them, including 12,331 with verified work emails and 6,340 with mobile numbers. Austin is the largest hub.
This list covers open source software companies headquartered in the United States, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, how directly it supports the match, and when it was last checked. Data refreshed September 5, 2026.
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 21 largest open source software companies based in the United States
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 24,404 | ||||
“Red Hat is the world’s leading provider of enterprise open source solutions, using a community-powered approach to deliver high-performing Linux, hybrid cloud, edge, and…” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 2 | 1,512 | ||||
“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…” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 3 | The Linux FoundationPartial evidence | 843 | |||
“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…” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 4 | QuansightStrong evidence | 45 | |||
“Quansight catalyzes sustainable innovation by connecting enterprise needs with community driven open source.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 5 | HosstedIndirect evidence | 22 | |||
“Enterprise support for your entire stack powered by a self-hosted AI agent that runs entirely inside your perimeter, with human experts one escalation away.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 6 | 16 | ||||
“The core mission of the Apereo Foundation is to assist and facilitate educational organizations which collaborate to foster, develop, and sustain open technologies and innovation…” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 7 | Unison ComputingIndirect evidence | 12 | |||
“Unison Computing is a Delaware public benefit corp.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 8 | 12 | ||||
“BlissLabs aims to build & maintain various open-source OS & Software projects for education & the community.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 9 | Nonadyne,incIndirect evidence | 12 | |||
“Nonadyne Inc was founded in 2013.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 10 | Ruoom INCStrong evidence | 7 | |||
“Free open source code you can run and adapt.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 11 | ThenewbostonStrong evidence | 7 | |||
“Open source development community.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 12 | OSS ConsultantsIndirect evidence | 6 | |||
“OSS Consultants is a business dedicated to helping organizations of all sizes - from the world’s largest and well-known companies to small businesses and start-ups - design…” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 13 | Unity FoundationStrong evidence | 6 | |||
“Unity Foundation leverages open source software tools and systems to provide more equitable access to the information and services that support a community’s needs, with a focus…” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 14 | GNU FoundationIndirect evidence | 1 | |||
“GNU FOUNDATION is a company based out of PO BOX 29301, SAN FRANCISCO, California, United States.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 15 | Linux4hopeStrong evidence | 1 | |||
“Linux4Hope is a non-profit organization serving the community through education of Linux and open source software and providing related resources to empower individuals with…” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 16 | Digica LLCStrong evidence | 1 | |||
“We are a team of passionate technologists introducing Open Source Software and it's advantages to individuals and small businesses.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 17 | SarapisIndirect evidence | 1 | |||
“Sarapis envisions a world in which people can access and own the technology they need to create just, abundant and sustainable societies.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 18 | 1 | ||||
“Providing strategic advice to companies looking for open source and business expertise- using open source to enable other business objectives (e.g, platform enabling, integration…” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 19 | Nexusoft LLCPartial evidence | 1 | |||
“Software for creators” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 20 | Matthew Kehrer SoftwareIndirect evidence | 1 | |||
“Welcome!” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 21 | 1 | ||||
“AngryStatic is a web-based community dedicated to open-source solutions.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
Showing 21 of 101 open source software companies based in the United States
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Open source software companies based in the United States at a glance
As of Sep 5, 2026Companies by employee count
Verified emails by last verification
How this list was built
Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among open source software companies, so some rows will be adjacent to the category rather than pure plays. The description and evidence rating on every row are there so you can check each match yourself.
- 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.
- What qualifies
- Companies headquartered in the United States whose own description of what they do matches “open source software companies”. Matching reads each company's description, not its industry code or its name.
- What we exclude
- Companies whose own description does not clearly place them among open source software companies, and records with no verified work email. Companies headquartered outside United States are excluded even when they keep an office there.
- Match quality
- In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and an evidence rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
- 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 listed company carries at least one verified work email, 12,331 across the full list. 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 September 5, 2026. Lists refresh periodically as the graph is re-checked.
- Corrections
- Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.
Frequently asked
How many open source software companies are there based in the United States?
RevenueBase identified 101 open source software companies headquartered in the United States as of September 2026, matched on each company's own description of what it does rather than its industry code.
What is the largest company on this list?
RED HAT, headquartered in Raleigh, tops this list with the largest team on record.
Which city has the most open source software companies?
Austin leads with 7 headquartered companies, followed by San Francisco (7) and Los Angeles (4).
How do I get contact information for these companies?
A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 12,331 verified decision-maker contacts tracked across these 101 companies.
How current is this list?
The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 5, 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.
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