[topicmapmail] Open Source Options?

[Gary Kopp]

Warning: newbie is here. I have studied the theory and application of topic
maps, and I would like to use them in the building and management of
thesauri for various technical writing projects. But from what I've been
able to determine this is a technology that is currently only being served
well by various commercial companies, all of which seem to have set
relatively high prices for their topic map "suites." There are some open
source APIs (TM4J and PHPTMAPI), but no actively maintained open source
topic map creation/editing software that I've been able to locate. The
closest I've come is Wandora, which is only "free" for non-commercial use
(and I haven't found anything concerning pricing for commercial use).

Am I missing anything? I'm thinking about building my own editing
environment using, say, TM4J, but in the interim I would sure like to be
able to create and edit topic maps with an inexpensive, preferably open
source, tool. If such a beast doesn't exist, another option I'm considering
is creating thesauri using SKOS, taking an RDF-based approach. There isn't
much tool support there either (there is at least one open source editor,
ThManager, that might suit me), but my gut feel is that custom coding around
SKOS/RDF would be easier than around a TM API, especially since I can hook
into existing RDF editors and extend them to deal with the SKOS vocabulary.

I guess a topic maps forum isn't the right place for me to march out my
brainstorming on topic maps vs. RDF approaches to thesauri. My real question
is whether I have any "inexpensive" options for off-the-shelf topic map
editing software.

--Gary Kopp