If you area a developer then you can redistribute the game and modify it freely as long as you abide by the GPL or you can even use parts of the art and sound for your own projects as long as you abide by CC BY-SA.
The new features from development team :
- Remake of many models, animations and textures, two new music tracks
- Configuration-free Multiplayer Hosting
- Capture the Relic Gamemode
- Aura and Heal Range Visualization
- Twelve new maps, including scripted enemies, rising water and a tutorial
- Espionage Technology, Team Bonuses and Hero Auras
- Petra AI Diplomacy and Attack Strategies
- Summary Screen Graphs
- Cinema Path Editing
- Buddy System