All of the different commands for the client
A more descriptive list can be found for player commands: here and dm commands: here. This list is definitive as of September 2004, but not yet fully organized. It taken from the source code and formatted. It still needs to be sorted and categorized.
This list is intended to be accurate, so please don't recategorize anything unless you're absolutely sure. That means don't move a command from “Not yet categorized” to where you think it should be, but aren't sure.
EditMe : Give a brief description of each command, and finish categorizing commands. Annoyingly, this requires testing each command to make sure we're accurate.