Исходный код sam:
sam -d can be used without X (with an ed-like interface -- but with more powerful regexpressions, the capacity to edit multiple files with a single command, and unlimited undo). Files can be added to an exiting sam session using the B command.
sam without the -d option is an graphical editor with pop-up menus and a point+click interface. You'll want to read sam's manual page to use the full power of sam, but you can probably figure out how to do basic editting with a minimum of trial and error.
If you have a Plan 9 terminal, you can use the Plan 9 terminal with sam to edit unix files, but not vice-fersa; the Plan 9 authentication scheme does not honor remote execution requests from a non-Plan 9 system.