Eric Freese has released version 0.71 of
SemanText, an application for representing semantic networks with topic maps.
The Python application is now open source, released under the GNU public license. It does not yet support the XML Topic Maps standard, but is likely to shortly. Freese explains the function of the program:
Semantic networks are a building block for artificial intelligence
applications such as inference engines and expert systems.
...
SemanText builds a knowledge base, in the form of a semantic network, from
the topic map. New information can be added to the knowledge base and topic
map automatically when the user defines rules which are used to infer new
knowledge.
He states that the advantage of using topic maps is that the knowledge base is then easily interchangeable.