Free/Libre Open Source Software
The term Free/Libre and Open Source Software (FLOSS or FOSS) was popularised by a June 2001[1] to October 2002 European Commission project on the subject. In July 2002 a Survey and Study report of the workshop portion was produced and garnered wider publicity for the term. The term combines the concepts of free and open source and emphasises the 'libre' meaning of the word free rather than the "free of charge" meaning which those unfamiliar with the subject might assume.Common meanings of free and open source are those given by the Free Software Foundation (FSF) and the Open Source Initiative (OSI). Their definitions are not all-inclusive, for they exclude some open source projects, such as anti-spam tool projects which allow unpublished commercial derivative works but prohibit selling derivative anti-spam tools with spam.
The term Open Source Software refers to software released under a license approved by OSI. As such, the software is usually free in the libre sense. The term FLOSS adds the term free to emphasize software that is also free as in gratis or free beer. Most free software is free in both senses.