[wfarr]

It makes /usr/local owned by the current user rather than root. Not much in the way of voodoo. ;)

It's basically a replacement for MacPorts.

[snprbob86]

See this section of the hierarchical filesystem guidelines for unix-like OSes:

http://www.pathname.com/fhs/pub/fhs-2.3.html#THEUSRHIERARCHY

and in particular:

http://www.pathname.com/fhs/pub/fhs-2.3.html#USRLOCALLOCALHI...

Isn't root supposed to own that?

[wfarr]

They're guidelines.

In the case of OS X laptops, they're almost uniformly used as single-user machines. This just takes the hassle of having to sudo to do it.

There are a few other reasons they specifically opted for /usr/local instead of other paths here: https://github.com/mxcl/homebrew/wiki/installation