Excalibur hasn't been released yet, and I think they developers recently said it is only in the Pre-Alpha stage of development. It was originally intended to be a mod for Star Trek: Bridge Commander, but they decided to make it a separate game, and it is being built on the NanoFX Evolved engine (and it's my understanding that the engine is being built alongside the game). So far, everything I've seen looks promising.
And yes, it is fan made, and is expected to be freeware.
You can check out there YouTube channel here
, and you can check out images of the ships and stations they've developed so far here
, along with some other things including animations and interiors.
I will show Ilithi your post and perhaps he will join Starfleet Jedi, assuming he isn't already a member.
Personally, I am still of the opinion that the Sovereign-class is stronger. She performed admirably in Nemesis and kept up a good rate of fire throughout the entire battle. One thing I have noticed about Galaxy-class ships, especially the Enterprise-D in particular, is that while they have demonstrated a good ability to unload lots of weaponry at once, they never follow through. I'm thinking the torpedo reload and phaser recharge times are slow, perhaps because they rely on only one fore and one aft torpedo launcher, and the forward phaser arc is primarily covered by only two, long phaser strips. Ships developed after the Galaxy and Nebula-class seemed to have moved away from their tactical design, and began using multiple, smaller phaser strips and multiple torpedo launchers.