Common:

Useful handlers:

cgi-bin/200.py : descruibes request, returns list of headers
cgi-bin/links.py?key=example : creates list of links with given key
cgi-bin/login.py : shows headers, set cookie; List of logins are here.
cgi-bin/say.py : shows headers, query, ip
cgi-bin/429.py : 429 trap (help is iniside)
cgi-bin/301.py?help : redirector, saves params, can redirect anywhere

Js checks:

js.html : js checker
frames.html : frames inside frames inside frames

Http codes: