for developing LUA, for non-work stuff I use SCITE, which is quite good (available from the lua.org website), it compiles the LUA code and throws out any LUA errors. Unfortunately, it won't detect any GameGuru native commands errors. But at least you know the syntax will be correct and that you haven't missed any "end" statements for example. It won't prevent runtime errors. Still it's all preference at the end of the day and I still use NOTEPAD.
Professional Programmer: Languages- SAS (Statistical Analysis Software) , C++, C#, VB, SQL, PL-SQL, JavaScript, HTML, Three.js, Darkbasic Pro (still love this language), Purebasic, others
Hardware: Dell Precision 490; AMD Radeon HD 7570; 12GB.
FPSC to GameGuru Tools: AutoWelder/SegAutoWelder, Entity+Weapon Welder, FPEtoBAT