Edit text with vi(1) by Roman Zolotarev
vi is not vim by Hugo Daniel (thanx @gaborkiss)
vi help by Jeff W
vi reference by Maarten Litmaath and James Hu
vi editor cheat sheet by ericg
Graphical vi cheat sheet by ViEmu
The vi archive and FAQ (a mirror) by Ove Ruben R Olsen
Annotated .nexrc by Sehnsucht