HTML to Wiki syntax converter
Another HTML to wiki syntax converter, also based on HTML::WikiConverter perl module.
html2wikipedia, a simple tool (filter) that translates HTML into the wikipedia wiki format. It's designed for Unix-like systems (including GNU/Linux), and I've been told it runs fine under Cygwin if you install that first. It should run on Windows, but that is untested; you should be able to use an arbitrary C compiler (such as gcc for Windows, MinGW) to just compile it.