I think you'll be lucky to have the kind of problems you're worried about. A lot of open source projects have one developer and no users. (Which is fine, we a

I think you'll be lucky to have the kind of problems you're worried about. A lot of open source projects have one developer and no users. (Which is fine, we all have itches to scratch.) Definitely pick a license. Permissive if adoption (particularly commercial) is more important to you than reciprocity, copyleft otherwise. The other thing to remember, if your work is any good, is that you have a big head start on doing whatever it is you're doing that makes your engine better than others, and you probably have even better ideas in the pipe. Open-sourcing this project is an expression of confidence in your own ability to come up with something better in the unlikely event that worse comes to worst and the project somehow gets hijacked. One word of warning -- there are probably more open source game engines out there than anything else, including actual open-source games. Your project has a lot of competition and may not gather a lot of attention unless you work hard to sell it.