Jean-Claude Wippler has written a package called tequila1 that allows Tcl arrays to be shared and persistent.
The tcllib tree structure2 that tkoutline uses is built on top of Tcl arrays and should theoretically be useable with tequila.
This requires changes to tkoutline, though. In order for it to work, the outline display in tkoutline would have to "react" to changes in the underlying tree structure. I think this type of change results in a better design, so I plan to look into it independent of whether I decide to try and integrate use of tequila.
One problem with the way I'm going about the "reactive" display (setting variable traces on the underlying Tcl arrays) is that it breaks the data abstraction layer that the tree library provides. Oh well, I'm not too bothered by that--it's fun to play around with. --06/09/02
One thing this reminds me of is a recent article I read by Jon Udell about what he calls "instant outlining" at http://www.oreillynet.com/pub/a/webservices/2002/04/01/outlining.html.