Quark is a fully modular mod with the objective of improving the vanilla gameplay experience. In other words, I would call it "what I would add if I was hired at mojang - the mod". Modules can be turned off and all features can be turned off individually. Some even have more in-depth configs.
Note: newer versions of this mod require AutoRegLib.
Check out the website for the feature list!
Join us on Discord:
If you have any problems with the mod or just want to contact me, you can find me on Twitter (@Vazkii) or IRC (#vazkii on irc.esper.net).