4chan's patched Shiichan code has been released upon world4ch /prog/ for a while now but you can snatch it at:
http://mihd.net/8ivnguj
http://massmirror.com/bc62b34134b56724154c77d2b89f61cb.html
Nobody's mentioned img0ch, it's the script used on nico nico douga's text boards. I think one of my sorta side projects for this semester will be taking a stab at translating it.