Editor, Hack, Second Life

This project is long abandoned.
Surely there are better solutions around by now, but if you insist, some slightly less outdated property files are available from Adam Marker's site.

SciTE-ez is a customized version of SciTE, the Scintilla Text Editor, bundled with WSciTEcm and wrapped into an easy to use installer. It's aimed at users of Second Life and contains support for the LSL scripting language of Second Life version 1.6.0, but also serves well as all-purpose text editor.