In the follow up of open-sourcing our project, I spent some time today figuring out which license would be used best. This was completely new to me so I started comparing the different kind of licenses available. Apparently there are two major kind of licenses. On the one hand you have the 'GPL based' licenses, which enfore the code that use the open-source GPL code, to also be free and to also continue under the GPL 'flag'. They even have a clause stating that you cannot add additional restrictions on the 'redistribution of either the original work or a derivative work'. The goal is to not only garantuee the 'freedom' of the open-source software, but to also encourage software that uses open-source software to do the same.
On the other hand you have a bunch of 'proprietary compatible' licenses, like the MIT/X, the BSD and the Apache license which pretty much allow everything (use, modify, redistribute, ...) without enforcing extra constraints. Chances are high that we will go with an Apache license. Somewhere in between those major kinds, there also is a more pragmatic version of the GPL, called the 'Lesser GPL' which literally is a copy of the GPL exempting the fact that the propietary software should also use GPL.
I also read a lot about copyright, copyleft, dual licensing, trademark protection, and credit enforcement, but I'm not gonna bore you with that...
