Open Source Community for Infrastructure Software

Project of the month: SAT4J


SAT4J offers a simple and efficient library of SAT solvers with reasoning tools in Boolean variables for Java. The Sat4j library targets first users of SAT "black boxes", willing to embed SAT technologies into their application without worrying about the details. The software was downloaded 200,000 times since January 2006, ranking 15th among the OW2’s most downloaded projects. Daniel Le Berre, SAT4J project leader, was awarded by the CNRS in 2018 and received the Innovation Medal.

News and Events



On September 5, we encourage all members and contributors to tell their policy makers how Article 13 will affect the preservation, sharing and improving of code. Follow easy instructions here or go directly to the #SaveYourInternet #DeleteArt13  website.



OW2con'19 Call For Presentation is open! Please check out the details of this year's main theme and topics and submit now!. (Deadline: March 17). 


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Why is tax-funded software not published as Free Software? OW2 supports the Public Money? Public Code! campaign steered by the Free Software Foundation Europe (FSFE). Sign the Open Letter!



Great result for OW2 projects and members at the "Champion of Free Software" contest organized in the framework of Paris Open Source Summit. 



OW2 will participate in the Paris Open Source Summit this year again on December 5-6, with a large community booth and a significant contribution to the conference program. Contact us to know more. 


How can you take part in the Community?

What is OW2

OW2 is an independent community dedicated to open source industry-grade enterprise computing infrastructure software, including middleware, application platforms and cloud computing technologies.

Why Join OW2

Make a stand, focus your open source efforts, help steer the community, increase your open source visibility, promote your projects, and join renowned industry leaders, SMEs, academics and individuals.

Free Infrastructure Software

OW2 hosts some one hundred open source projects spanning application platforms, components, middleware, cloudware and tools for the development, deployment and management of distributed and cloud applications.

Submit a Project

At OW2 it usually starts with an open source project. We provide resources, governance and help build awareness for your project. Checkout the project life cycle and fill in the submission form. Join the code base.

Quality and Trustworthiness

Enhance the quality and facilitate the market adoption of your project with the unique suite of tools freely accessible with Open-source Software Capability Assessment Radar (OSCAR) the OW2 quality program.


Check out the beta version of OW2 marketplace at EU-funded project AppHub. Stay tuned for future development and full opening of the marketplace to OW2 projects in 2017.

Download OW2 Software

Infrastructure Software, Application Platform, Middleware, Tools

The pioneer's time is over
The future is bright. And only people who have the courage to change can push innovation forward. ... more

Collaborative Projects

Leveraging open source to foster collaborative innovation is a powerful strategy. OW2 is an experienced Open Source Software community for collaborative R&D projects. We provides community support and dissemination services and community building services to multinational open source collaborative projects and large collaborative R&D projects. In particular, OW2 has established itself as the reference dissemination and community platform for complex government-supported, open source-oriented projects.

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