I also think there's some room for a nice, simple text editor which has some options like syntax highlighting, line numbers etc., maybe auto-indenting and a scripting interface to allow compilation from the menus, though this isn't essential. As an example, I carry Notepad++ around with me on a USB drive. It does what I need and is pretty small. It's also open-source, so maybe a partial port or some borrowing of features might be possible?
