I'm not generally vey enthused by outliners myself : too hierarchical for my taste - give me a rhyzome of pages any day. :-)

But I am intrigued by Dave Winer's coming OPML product which will allow a small group to share a tree of outlines. I don't think that's a combination (client-based, http protocol, shared, hierarchical) that we've seen before.

Comment On ExpandingBrain, a blog dedicated to outlining.

expandingbrain.com/blog/

also has a "Decline of outliners" story : expandingbrain.com/blog/

Another thing I forgot to mention, I find I'm starting to write a bit of an outliner now in SdiDesk.

I didn't plan to. I was simply trying to nail some bugs in the code which renders the nested bullet lists. However, the code was getting a bit long and convoluted, a so I realized I needed a more coherent way to parse and process it. In the last week, I've found myself writing a NestedBulletList class which is essentially a recursive tree structure to represent these lists, and which also handles the parsing and rendering of them.

It could easily be adapted to allow sub-trees to be hidden or not and provide some other outliner-like features. I already record whether items are "checked" etc. I could record whether they're open, or the estimated time, or the percent done, too. (I have some Perl which already does something like this from a couple of years ago.)

Not sure I want to go that way yet. What's more likely, short term, is that I'll make outlines a separate page-type, the way network diagrams and tables are. This would allow me to have a special edit modes for them, as with these other types, that could include a standard expanding / collapsing view.