Revised Nov 1 2008: Draft of OWL2 specs.

The recent drafts of the OWL2 specification describe some important changes from OWL1. In a nutshell,

The structural specification of OWL 2 provides the foundation for the implementation of OWL 2 tools such as APIs and reasoners. ... This document also defines the functional-style syntax, which closely follows the structural specification and allows OWL 2 ontologies to be written in a compact form.

Revised Oct 27 2008:

Maybe I should use a pseudonym for this posting ....

Revised Oct 20 2008: This is a new "hybrid rule engine" category for the development site, more nut-and-bolts-oriented than most rule engine discussions.

What I call "un-rule engines" are rule engines without true inferencing capabilities. How can they be called rule engines ?

This is a new topic ... it is more abstract than most content on this site and may be moved to the Home site.

Updated: Sept 17 2008, more links

Note that there is some overlap in the use of the term "rule engine" with pattern matching, text transformation, rendering and other filtering or search engines that have some level of rule capabilities.

A nascent category for "associative" engines, neural networks and various statistical and connectionist approaches to inferencing.

Updated Sept 19 2008: more links for Ruleby

Not a major category among the many rule engines implemented in Java and other languages, but some of the implementations are solid and interesting.

In fact, Ruby rule engines are particularly interesting because my hosting service ( Hostmonster ) provides them as installable Ruby gems. The Radiant CMS is also available as an application platform to connect the rule engine to the outside world.

Updated Sept 24 2008: added features and SWCL link

Updated Sept 16 2008: Note that this is not a complete list of Java workflow applications, just the ones that I have found and interest me.