FOSSCOMM (Free and Open Source Software Communities Meeting) is the pan-Hellenic conference of free and open source software communities. It is addressed at programmers, students and anyone else interested in the open source movement, despite their background. Participating communities include the Hellenic Linux User Group (HELLUG), contributors of open source projects such as Mozilla, Fedora, OpenSuse, KDE and more. The content of the conference includes a wide variety of topics ranging from technical issues and workshops to translations, legal issues, political issues concerning open source software/hardware, etc. The attendance of the conference is free of charge.

FOSSCOMM is usually attended by a few hundreds of people, with the largest number having been recorded in Patras in 2011 with about 450 participants. It is held on an annual basis since 2008 and till today it has been organized in 6 different cities. Everything is organized and set up by volunteers and financing comes from sponsorships and donations.

Traditionally the conference is held at universities, with the event of 2017 having been held at Harokopio University in Athens. At the end of each FOSSCOMM there is an open call for the organization of next year’s event and a committee comprised of volunteers of previous events chooses among the submitted proposals.