in reply to
newb: Best way to protect CGI from non-form invocation?
The most common tactics is to use a captcha, but like all methods that seek to keep bots out (and humans in) it has weaknesses. The comments in this thread discuss this problem.
Compiling them myself
Merijn's HP-UX software
Whatever is shipped with my OS release
None, i use PerlScript
Results (172 votes),