They're running Bravo. That's a fun editor. An improvement on most of its successors.<p>You edit both programs and documents in Bravo. Programs in Mesa are usually written in variable-width fonts. (Somehow this never caught on. It looks nice. I used to bold Mesa keywords.) The file format is plain text, then a control-Z, then formatting information. The compiler reads up to the control-Z and stops, thus ignoring the formatting.