zsIRC is an IRC-client for the Pocket PC

zsIRC has the usual "/cmd" command syntax:
/raw
Sends a raw command to the IRC server.

/join [password]
/j [password]
Joins a channel

/query
Opens a query window to a given user

/nick
Changes your nick

/me
Uh... hard to describe, you should know it already.

/mode [channel] <...>
Same here. The typical /mode command

/part [channel] [message]
Leaves a channel. if you don't specify a channel, it leaves the active one.

/whois
Useless data about a given user

/msg
Sends a simple message

Download IRC_2006_06_13.zip

Source