The allgear format is just as the name implies, you may use any hardware or software tools you desire! However... please keep in mind that in an allgear remix, you MAY NOT use any outside samples or sound generators. Feel free to go wild with the effects though.
It says on the right there that you can only submit mp3, but you can actually really submit any format you wish. So long as it's within the rules of the compo (we need more submit anything allgears).
The allgear format was once frequently confused with the wildcard (now wildchip) format. Wildchip is and was always a chiptune format only, while allgear has a world of possibilities including chiptunes.