Missed the poll
I use a combination of:
- TextPad for general text file editting (with MP's syntax file)
- VLIDE to catch syntax errors, and to help identify variable names for localization
- extinct 'Ally - A Lisp Analyzer' by Steve Wasco (shareware version) for variable and function reporting and finding parentheses matching errors
Ally has the best parenteses matching I've seen (and I've been using AutoLisp since inception with Acad v2.18 c 1985). Uses a different colour to display parentheses at each nesting level, and blinking parentheses to show a mismatch. See screen grab. Also has a simple 'single line' editor to make quick fixes. I think that Ally evolved into another product named 'Cadet'.
Disadvantages of Ally is that it is a DOS program with limited window size and works best if DOS compliant 8.3 filenames are used. I run it using DosBox (accessed via batch files called from an AutoLisp file).