This is under discussion - just some facts collected to this page ATM.
WinMerge 2.x is licensed under GPLv2.
There is an initiative to double-license WinMerge 3.x as LGPL + GPL. Our suggested new component stack allows that.
GPL (and LGP) aren't very good licenses for documentation. Perhaps we can use for example GNU Free Documentation License instead. Or some other more documentation-oriented licenses.
The GNU Free Documentation License has not the best reputation for documentations. Maybe we should use a Creative Commons License? Wikipedia use for example the Attribution Share Alike license. --gerundt