I declare...backward chaining suits me fine!

...that declarative programming has many advantages over imperative programming in the
modern context of creating smarter transaction / query / test / search systems.   My two
favorite declarative tools right now are Pellet and Prova, both of which are open source java
SemWeb tools that are highly compatible with Jena, which recently got a bump to 2.3 with
fairly complete SPARQL support.    Pellet is an implementation of OWL-DL and some related
description logic facilities by the Mindswap guys in Maryland, who have absorbed some of
the l33t Kowari/Tucana guys, too (Tucana was recently picked up by Northrop, BTW).   

These three tools, folks, together with Laszlo or AJAX on the client, are a perfectly lovely alternative
we have now and forever to whatever shiny semantic doodads Microsoft dangles in front of our
occasionally less-than-discerning general IT population when the Longbone WinFS triplestore finally
gets its $1B TV commercial next year.   Oh, I'm chafing to know, who will be the spokesmodels? 
I'm hoping it's John Madden and Catherine Zeta Jones, explaining how the semantic future has
arrived through a series of incredibly witty and erotic super bowl spots, maybe punctuated
by Gwen Stefani and Carrot Top in some kind of steamy jungle Shakespeare parody.  Whatever
they do, I  predict M$ will get at least a 6-month Windows-95 "The semantic web is finally here,
because Microsoft says it is!" kind of wave, and tech stocks will run up somewhat on that.   Email
me for other hot stock tips and tomorrow's picks for Golden Gate Fields!

But my big question is: How little if any RDF/OWL compatibility will M$ shoot for?  Perhaps
a winderz-Maven can clue me in.    For those who are married (willingly or shotgun-style)
to Microsoft as a dev platform I will again suggest RDFGateway as a very nifty and highly
standards-compatible native Windows (C or C#) implementation of an RDF+rules portal for
windows (free for personal use, pay for commercial use).    Runs like a dream, though I've
seen the rules engine get slow if you trick its optimizer.    One neat feature is that it will
monitor it's own query performance and draw you a picture of the query plan with performance
annotations.  Schweet!

Back to them big 3 open source java tools (Pellet, Prova, Jena):  While the Jena is a wonderful piece
of code for which HP's SemWeb group deserves a lot of credit, and the Pellet seems to be
coming along nicely and being well received, the Prova is a bit more off the beaten track,
and probably represents a more idiosyncratic choice of tools on our part.    Allow me to esplain.

Prova is a prolog-variant built on top of Mandarax.  It is a very effective and fun medium for scripting
of high-level relationships and operations.   The integration of prolog unification, java types, java
methods, and java exceptions is done very nicely, and yields fine code economy.   There are some
rough edges in the docs, but we are helping to get these worked out in the pretty soon.