Chrono Trigger (SNES)

Utilities

Temporal Flux coded by Geiger (Evil Peer), written using the Microsoft .NET framework, is the principal Chrono Trigger hacking utility. It is available at Geiger's Crypt. There are also a few hacking documents available there.
CTEP - Chrono Trigger Editor Companion coded by JCE3000GT. Designed to be a companion to Geiger's/Evil Peer's Editor. It edits some things his does not.
SPC Editor coded by JCE3000GT. This utility allows the user to edit the instrument sample indexes in various games including Chrono Trigger.
Chronotools, Translation utility. Bisqwit's chronotools page

Complete:
Pera Wish

Partial:

Prior to Temporal Flux's release, a teaser "trailer" was released to keep the community guessing as to what exactly TF was.
Chrono Trigger: Crimson Echoes was a big hack that was in the works prior to receiving a cease & desist letter from Square-Enix. A short demo has been leaked.
Chrono Trigger - Time's Illusion is another big hack that was in the works. There is no date for a demo as of yet. Due to the Crimson Echoes C&D, development has ceased on this hack as well.
A minihack called Chrono Trigger Coliseum has been released, created using the Temporal Flux utility.

Bisqwit made a Finnish translation for the game.
Manuloewe translated this game into German. Version 1.01 can be downloaded here.
GreekRoms has a partial translation for this game into Greek. It is available for download here.
SadNES cITy has translated this game into Italian. It is available for download here.
CTTT has a partial translation for this game into Polish. It is available for download here.
CBT translated this game into Portuguese. It is available for download here.
DarknessSavior has started an English retranslation.