Alliance are a serie of different mods. On the Star Wars GC, you can play the civil war Empire vs Rebel era + Black Sun and soon the Republic and CIS.
You can see some new units from Black Sun at action. The Geonosian Dreadnought, the Secutor or a new Heavy Artillery space unit.
You can find these new units in the last 6.5b+6.54b patch. Only at Firefoxccmods.com