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.
While I finish the last version. You can see a preview from these changes:
Some textures improved by Nawrocki.
Changes in the splash screen by Nawrocki.
The starbases does not fire a super shot.
The new starbase reinforces.
Bilbringi adds a ground map.
Fresia ground map has some additions.
Space Fighters/Bombers are bigger at scale and now you can see clearly their laser proyectiles.
There four new ship upgrades for the Empire, all them for the Imperial Star Destroyer MKII. Now you can upgrade it to one Dominator, a Artillery ISD, a ISD2 deploying TIE Avenger, a ISD2 deploying TIE Defender and TIE Avenger, and a ISD 2 deploying Missile Gunboat, TIE Defender and TIE Avenger.
The proyectiles from the Missile Gunboat has been fixed and it fires advanced torpedoes again.
Some fixes at different ground and space maps.
Some multiplayer fixes from some galactic conquest as the Clone Wars GC.
New missile and advance missile trail effect.
Changes in all the weapons from the space units making their fire more realistic.
The Skirmiss Starbase from Black Sun has some changes in the units objects builded. Now you must not make some upgrades if you want upgrade the station.
Less ground units firing in the air ground units.
Imperial scout makes less damage but it has better resistence to the damage.
TB2-AA and AT-AA can not fire at nothing more than air units.
Well, you can see some of these things at this video.