WML-Wireless-Markup-Language-syntax is a project mainly written in Vim Script, it's free.
The title says it all
This is a mirror of http://www.vim.org/scripts/script.php?script_id=643
I found no syntax script for wml so I made a simple one.
It was made for WML 1.1. Other WML versions weren't taken into account, but I believe this file is very easy to change.