Dave Winer has been releasing updates to Little Outliner, which is a browser based implementation of his outlining tools.
Little Outliner creates and edits outlines written in OPML, which is an XML-based file format for outlines that Dave created. If you only need to view and edit files, Little Outliner is all you need. Dave recently released a web service that renders an OPML file as a web page, the net result is a simple way to create a nice looking web page. I’ve decided to use this to create my /now page, all I have to do is edit the file in Little Outliner. You will find the link to this page in the footer the pages on this site.
You may notice that the subheads in the page have a littlle upside down triangle, those are parent nodes of the source outline, the following indented text are children nodes. If you click the triangle the node will collapse, click it again and it expands. By default all of the nodes render as expanded but you can configure a node to collapse by default. Click node you want to configure as collapsed, then click the suitecase icon on the left toolbar, click the plus button on the Edit attributes window; in the left field enter collapse, in the right field enter true, and then click Save. Refresh the web page and you see node/head you configured will be collapsed.