Simple-vim-installer is a project mainly written in Ruby, it's free.
When you want to compile vim from source with all patches, options, and language support enabled.
This script will compile a fully functioning vim executable on your system. You then put it wherever you like (in your path) though you probably want to replace the stock vim on your system.
Though any system can use it to compile the most up to date version with all patches, its geared toward Mac OS X users who don't want to use MacPorts, or found some configuration item not compiled in the stock version.
Also, please note that this does not come with any plugins, though I have some favorites I would suggest: Rails.vim, Fugitive, Grep.vim, tComment, among others.
Any questions/requests please don't hesitate to send me a message.