Amaranth is a powerhouse of personal productivity tweaks by Pablo Vazquez. Check out his 20 minute(!) walkthough.
Using Blender every day, you get to change little things on it to speedup your workflow. The problem is when you have to switch computers with somebody else's Blender, it sucks.
That's the main reason behind Amaranth. I ported all sort of little changes I find useful into this addon.
What is it about? Anything, whatever I think it can speedup workflow, I'll try to add it. Enjoy!