X-tra: StarEdit mod
StarForge: Third party editor
SCM Draft: Third party editor
ProEdit: Can unrecycle strings if StarForge recycles them (tends to screw up recycled comments though)
uBeR@TiOn: Map protector
MS Sound Recorder: Bloody invaluable when converting sounds to .WAV and editing sounds
SC Trigger: If you want triggers for kills without using a looping system
Trigger Duplicator: Allows you to make many triggers that are similar but just change numerical values