Short version: Please use the?GNU Affero General Public License for open.mp
Long version:
If I understand correctly open.mp will be open source once it's released to the public. This is great! There's only a small detail I realize just now about the specific license terms open.mp choose and what it could mean for the players.
First, if open.mp uses a non strong copyleft license, this could allow for third parties to create closed source versions of open.mp, and with the correct marketing they could even become more popular than open.mp itself. This would be terrible for the players because they will lose the freedom, convenience and other advantages that only an open source development can give. To prevet this I suggest using a strong copyleft license such as the GPL. This way, third parties are still allowed to modify open.mp's source code to their heart's content. But they will required to share the full modified source code when distributing their modified version. This will be beneficial to the open.mp developers because they will be able to merge popular changes.
Second, the server part of open.mp will be just as important as the client part. Taking this into consideration, another point also related to the first?must be highlated. And this is the fact that most licenses?don't prevent server owners?from modifying the open.mp server source code and not?release the source code to their users. This is because connecting to a server does not count as distributing in the copyleft context. To prevent this I suggest using a license that prevents this, such as the?Affero GPL.?This way, third parties are still allowed to modify open.mp's server source code to their heart's content. But they will required to share the full modified source code to the players connecting to their server.
Using the?GNU Affero General Public License for free distribution?could allow open.mp a way of monetization?by selling non copyleft licenses, there's lots of companies developing open source using this kind of business model.
Finally, what I want to prevent is closed source forks of open.mp becoming incompatible with the original open source version, I dont have any issue with open source forks of open.mp being incompatible?because as long as they are open source too, then open.mp can simply merge the changes to keep? compatibility if necessary.
For more information on the?GNU Affero General Public License:?Why the Affero GPL