For lua 5.0.3 (http://www.ptokax.org/files/Libs/PXLibMD5-lua5.0.3.7z)
For lua 5.1.1 (http://www.ptokax.org/files/Libs/PXLibMD5-lua5.1.1.7z)
Source (http://www.ptokax.org/files/Libs/PXLibMD5-src.7z)
Initializing in lua 5.0.3 like
libinit = loadlib("pxlibmd5.dll", "luaopen_pxlibmd5")
libinit()
Initializing in lua 5.1.1
require "pxlibmd5"
This will register global md5, more is in docs 8)