Bukkit

/gm - to switch your own gamemode (cgm.change)
/gm [mode] - to change your own gamemode (cgm.change)
/gm [target] - to switch others gamemode (cgm.change.other)
/gm [target] [mode] - to change others gamemode (cgm.change.other)
/gm get <target> - Checks players gamemode (cgm.info)
/gm info <target> - Checks players gamemode (cgm.info)
/gm get <mode> - Checks players in gamemode (cgm.info)
/gm info <mode> - Checks players in gamemode (cgm.info)
/gms - to set a gamemode to survival. (cgm.change)
/gms [target] - to set a gamemode to survival. (cgm.change.other)
/gmc - to set a gamemode to creative. (cgm.change)
/gmc [target] - to set a gamemode to creative. (cgm.change.other)
/gma [target] - to set a gamemode to adventure. (cgm.change.other)
/gms all - to set all player gamemode to survival. (cgm.change.other & cgm.change)
/gmc all - to set all player gamemode to creative. (cgm.change.other & cgm.change)
/gma all - to set all player gamemode to adventure. (cgm.change.other & cgm.change)
/gm help - shows a list of all commands (no permissions needed)
/gm version - shows the version of this plugin (no permissions needed)

Aliases:
cgm / gm

If there is a player with the name PlayerName, you only have to type: /gm p [mode]
But when there are the players with the names PlayerName and Palyername, you have to tpye /gm pl ... or /gm pa ...