GuyDude?
If you use a Node Implementation each tiddler is stored this way, but we do need a little improvement in this area. Bob also allows you to serve a files folder, perhaps you can write to that?. To export you need a trigger, typically a button, but there are ways to make use of an existing trigger like startup actions or even the save button itself. Where it gets a little complex is to get this to work in the different saver/browsers because writing to files (Especially local) is limited by browser security. There are way I can foresee but they are all a little complex and I would need research further to answer.
Anyone else?
Regards
Tones