CK 1-6
Provides cheats and cheat codes
http://www.cheats.ee/commkeen16.php
CK 4
Easter eggs found in commander keen 4 software. find hidden easter eggs in movies, televisie shows, software, music, books, and art.
http://www.eeggs.com/tree/645.html
CK 5
Easter eggs found in commander keen 5 software. find hidden easter eggs in movies, televisie shows, software, music, books, and art.
http://www.eeggs.com/tree/646.html
CK 6
Easter eggs found in commander keen 6 software. find hidden easter eggs in movies, televisie shows, software, music, books, and art.
http://www.eeggs.com/tree/647.html