The Playing Field project aims at using the Open Source concept as much as possible. We are using Open Source operating system and applications on our servers, which are part of the The Open Source Streaming Alliance(OSSA) a network of Open Source streaming servers located on three continents (Australia, Europe, North America) that relay and exchange their streaming content through multicast channels. Open Source licenses are used for Open Source projects and Free software. OSSA developed The Open Source Streaming License.

Definifions and documentation:
The Open Source definition
The Free Software definition
Copyleft is a general method for making a program free software and requiring all modified and extended versions of the program to be free software as well.
Open Source Initiative (OSI) is a non-profit corporation dedicated to managing and promoting the Open Source Definition.
Approved Open Source licenses
Copyright en digitale cultuur. Dutch only! Verslag van expertmeeting georganiseerd door het Virtueel Platform, 13 maart 2002.

Open source software: Debian is a free operating system (OS) for your computer.
Icecast open source audio streaming server.
Darwin is Apple's open source version of the BSD UNIX operating system that offers advanced networking, services such as the Apache web server, and support for both Macintosh and UNIX file systems.
Apache is an open source HTTP server for modern operating systems including UNIX and Windows NT. Apache has been the most popular web server on the Internet since April 1996.
The Frequency Clock is a open source software system created to manage streaming audio and video channels. is an open source streaming package with three components: station management for organising content and schedules at radio stations, metadata nodes for exchanging content, and a portal manager, including RSS feed.
phpGroupWare is an open source intranet/groupware tool and application framework.