ChocolateLiquor is a project mainly written in Vim Script, it's free.
low-contrast dark scheme
This is a mirror of http://www.vim.org/scripts/script.php?script_id=592
This started as an inverse/opposite of PapayaWhip (vimscript #591), but took on a life of its own. If you want a dark background that's very usable but without too much contrast, try this one.
Screenshot: http://home.ptd.net/~gwilliam/vim/ChocolateLiquor.png