Ten years ago, I lost the source code to Solar Realms Elite (SRE), a game I had worked on. Since then, many people have wanted to build a clone. I've tried to help them, both through email and by posting what I remember about the game's design. However, most of the projects had not gotten very far.
Yanick Bourbeau has built a web version of SRE called Imperium Galactica (which also happens to be the name of an older, unrelated game). It's fairly complete and offers a few things SRE did not (like simultaneous play by several players). I've been playing for a few days and it's fun! The game isn't quite balanced yet, but that will take a little bit of time to fine tune. Try it out!