I normally use the Atom editor, and since BE BASIC is a bit different from other BASIC flavours out there, I created a language package to use with it:
The repo is here:
It's nothing fancy, and it may be missing a few things here and there, so if you want to contribute, feel free.
I hope you find it useful.
I pushed a new version (v0.4.0). Removed the line numbering requirement. Made the commands case insensitive and added a few more attributes and command (SCALE, ANGLE and HELP).
Pushed version 0.5.0, with WGET, TFTP functions and OFF attribute.
Version 0.7.0, synced with v0.90-88 of firmware.