Whilst looking for a text-editor to use on my iBook I came across SubEthaEdit which is free for non-commercial use,
It isn't strictly a text-editor, more of a collaborative working tool. Being able to invite participants to edit a document, in real-time. It seems to handle code-highlighting nicely, and also 'tracks changes' by highlighting. I assume each editor gets their own colour, but I haven't had the opportunity to test out the networking capabilities.
Again, there seems to be no macro ability, but thats understandable within a realtime network environment, running a series of commands on a document which might be changing as it executes could cause havoc. There is a regular expression find/replace, which is not only this seasons must have feature, but also sanity saving when you're tidying up non-standards based code into something more elegant, or when variable names need rationalising through scripts.
What exactly defines a 'symbol' I don't know, but SubEtha lets you float to the next or previous ones. It seems to pick up heading tags as symbols, but not list items, a bit odd really.
However, the real point of SubEtha is the multiuser mode.The idea that documents can be constructed in real time by teams, instead of a feedback and control loop is interesting. But assembly-line methods are deeply ingrained in our workplaces, as are the task and tool orientated roles that go with them. Realtime multiplayer editing seems to cut through those kinds of structures. Questions of efficiency of new methods have to be answred before this kind of tool-work become widespread.
I'm not thinking about the collaborative note-taking and drafting exercises that most multiplayer editors are designed for, but the actual constuction of software, websites, or even narrative texts. In that respect a Flash Platform frontend to a Wiki could provide a similar, but much larger scope with many users. (Just Letters for example)
SubEthaEdit is not the +5 scroll of Text-Edit I'm looking for, but its unique multiplayer abilities means it gets to stay in my backpack.