Rxss is a project mainly written in Perl, it's free.
Find XSS on *your* website
Find XSS on your websites.
The idea is simple: find forms on a page, try different xss patterns on every field and check that after form submission the pattern is still there.
Usage:
$ bin/rxss localhost:5000
Provide your own patterns (take a look at patterns/simple.txt):
$ bin/rxss -p mypatterns.txt localhost:5000
TODO: