Open Source Licences
At the moment there are more than 50 OSI certified open source licences. The following five are perhaps the most commonly used:
The difference between them is the extent to which they control the way the code can be combined with other software. At the one extreme, the BSD licence permits open source software to be merged with closed-source code and then sold under a conventional licence. At the other, the GPL licence insists that if the software is combined with other code then that too must be under a GPL licence. The decision as to which open source licence to use on a new software project should not be taken lightly. In many ways it expresses and shapes the development goals of the project.
