Equivalent Exchange adds a lot of endgame content such as Nova Catlysts (TNT on steroids!) and Dark Matter.

Official Forum post: http://www.minecraftforum.net/topic/364525-100-equivalent-exchange-v573/

E.E. Wiki http://equivalentexchange.wikispaces.com/

E.E. is on the old version, and should be manually updated before creating a world.

Philosopher's Stone

Rubber

Equivalent Exchange

Automatic EMC Generation (faster than collectors)

Alchemical Chest

Covalance Dust

Energy Condenser

Video Tutorials