Commercial Open Source Software
FOSS can be sold and often is, for example with support agreements including telephone and rapid patch response, or with services agreements to match configuration to an organization's process workflow. And there isn't anything wrong with that according to most FOSS licenses. Indeed, to this day the primary product of RedHat, the most commercially successful open source company ever, is the FOSS operating system Linux.
Commercial Open Source Software (COSS) often contains elements of FOSS, however it also limits availability of some enhanced functionality to closed proprietary software, thereby creating a potential path to the same old vendor lock-in, and so does not qualify as FOSS as a whole.
Some examples of COSS are listed below. (Please only add links below to pages describing closed software requiring fees).
- ConcourseSuite (formerly Centric)
- Kolab - "These are collateral results of the following commercial activities: Uptodate, tested and supported packages for specific distributions can be ordered from the Kolab Konsortium."
From COSS to FOSS
Companies that thought about COSS but then decided FOSS was the better strategic decision: