From TFA:
The 32-bit version of Menuet was released under the GPL, but the 64-bit version uses a non-open-source licence that is free for "personal and educational use". Why did you decide to licence the 64-bit version differently? Has this had any impact on encouraging people to join the effort?
Ville: With a completely new type of open source project, people seem to have strong opinions about what direction to take. Even up to a point when time is actually spent more with disputes than doing the actual coding. And when that happened, I decided to concentrate more on the original path of Menuet with the 64-bit version and with a new type of license. However, I don't have anything against open source or possibly opening up the Menuet64 source later. But with the current licence, I'd say the people are a bit more committed and willing to put more effort in to a new feature.