An Efficient Link Store

• Another web of data store that produces a subset of RDF/XML, Astoria, is from an unlikely source, Microsoft. Instead of a proprietary Semantic Web, Danny sees it as going to town with URIs and REST.


• Silverlight was the other surprising Microsoft development, nothing beats running code - except maybe browser-based dynamic code 2000 times faster. Applets are cool again.


• Some ideas for static triple indexing "Most mature triplestores also index a 4th query element ‘graph’ or ‘context’. I intend to support this query type without expanding the index by using a trick: In my triples format the fact that the subjects are auto-generated and local to the graph means I can choose them to be sequential and effectively re-use them as graph indexes..."


• Plugged In/Invisible Worlds/Tucana/Northrop/TKS/TMex/Kowari/Mulgara podcast (links to the Talis page).


• PAGE a distributed triple store using DHT and YARS (the original). It does seem to miss the DELIS work on P2P RDF which scaled up to 64 nodes.


• Haskell and the Faith of Programming Languages Phillip Wadler gives a rather brilliant talk on programming languages. Covers Haskell, Java generics, combining different typed languages (weak, strong, very strong) as well as monads and Links.

Announcing Andrae

lca: Andrae Muys on RDF "On the first day of linux.conf.au, I ran into Andrae Muys. He hacks Java and RDF for clients who want semantic web hackery done. I have to admit that early Semantic Web hype put me off: it sounded too much like 1970s AI hype. Andrae was interesting, though, and completely free of the wide-eyed uncritical enthusiasm that characterized a lot of my early RDF engagement."

"Andrae runs the Mulgara project, a Java RDF store. His goal is to be able to deal with 1E13 statements (aka tuples, facts, assertions) in three years. It'll do 1E9 right now, next stop is 1E11. He refers to this goal as "3 Ts: three trillion triples". A consortium is forming around Mulgara to make this happen: if it coalesces, Andrae will be the coder to make it happen."

"The next version of Mulgara, 1.3, will ship in February and have this relational mapping in it. A quick Google search shows a lot of RDF-relational mappings going on, but the list of other mappings he had impressed me: Lucene, RSS, mbox, ID3."

"I think it's time I looked again at the world of RDF. They may yet be doing interesting things. I said as much to Andrae and he replied, "I am an engineer. In the early days it was scientists and logicians in RDF. Now the engineers have arrived, and we just want it to work and to scale." Bold claim! If you have a favourite RDF package or practice, let me know in the comments."

Andrae also announced the paper presented at linux.conf.au. Among other things it references David Wood's paper presented in 2004 "Scaling the Kowari Metastore" ("Makepeace" is a good search term).

The Classpath Exception

So I had almost exactly the same discussion with someone today about the GPL and Java that David Wood is alluding to.

Tim Bray has the answer: "Unmodified GPL2 for our SE, ME, and EE code. GPL2 + Classpath exception for the SE libraries. Javac and HotSpot and JavaHelp code drops today. The libraries to follow, with pain expected fighting through the encumbrances. Governance TBD, but external committers are a design goal. No short-term changes in the TCK or JCP.".

The Future is a little Brighter

David links to a posting he forwarded from the Kowari developers list (original post here) from Amit Kapoor about the future of Kowari: "The Topaz Foundation (http://www.topazproject.org) is very pleased to forward the email, from Michael H. Wallach (Senior Counsel, Northrop Grumman) to Richard Fontana...We trust that this letter will end any confusion with respect to the future status of Kowari, which has been secured, and that the community will now be able to focus on making Kowari one of the most vibrant open source projects."

"Northrop Grumman respects the rights that users of open source Kowari software receive under the MPL. Northrop Grumman intends that open source Kowari software, licensed under the MPL, is and will remain free, open source software.

Moreover, Northrop Grumman has no objection to the continued appropriate use of the "Kowari" name by developers participating in the Kowari open source project."

Northrop Grumman Killing Kowari?

Resignation from Kowari due to Northrop Grumman Letter "It is with sincere regret that I resigned as an administrator and developer of the Kowari Metastore."

"Northrop Grumman's position seems to be that they "purchased all rights associated with the Kowari software", a position not reconcilable with their continued release of the software under the Mozilla Public License, version 1.1."

So it would seem that Northrop, for whatever reason, dislikes Kowari's existence.

To get David and then Tucana (whose IP was eventually sold to Northrop) to start and continue with an open source version of TKS (the closed source version of the RDF database) was my little hobby horse (I fought fairly long and hard you could say). The idea was to get the Semantic Web bootstrapped and to create a value network around Semantic Web technology (I got this originally from "A critical look at object-orientation"). It is deeply disappointing for me to see it (the value network and Kowari) threatened in this way.

Like any OS project it is the ecosystem that is built around Kowari that makes it work. With so many contributions, just how much of the total code does Northrop actually own the copyright to? By accepting changes it isn't following the dual licencing model used by the owners of Berkley DB. To me Kowari was always using open source as a development and distribution model. Already, we have some contributors threatening to pull out their code (more at, "Disturbing News From Kowari").

Having administrators leave due to Northrop's actions is a good way to kill the project. Hopefully, Northrop's bullying will get a lot of interest - it's good to see, for instance, that this has been picked by aggregators like Topix's Aerospace and Defense.

The other posting David W linked to: Is Northrup Grumman Smushing Kowari?, "But I’d like to know what the status of Kowari is going to be, open source or not, because there are clients for whom Kowari might be the right choice, and we won’t bet on a dog that Northrup Grumman seems determined to publicly beat to death.

Relying on Kowari is now not prudent, given our obligation to do our best for our clients; but it’s also bad for Semantic Web uptake in the US federal government, and that’s something Northrup Grumman should think very carefully about."

Update: Paul and Andrae have also added their thoughts.

Update 2: David has published the letter from Northrop's lawyers. Danny posts, "...clearly if the current Kowari is MPL’d they can’t stop other developers working on the system."

More on Disjunction

I think this is just going to happen time and time again, "RDF non-sense": "The W3C Working Group members argue SPARQL is a mixed mode language that does support OR, though they are calling it an "optional union". Frankly, I see no point in renaming something people understand to mean one thing. It gives me the impression the W3C want to be thought police and enforce a certain way of thinking.

On the practical side, many analysts happen to like OR disjunctions and would complain loudly. Of course, there are plenty of cases where users abuse the power and write deeply nested disjunctions. That is not a valid reason in my mind to avoid disjunction. It saves the user time and allows them to write simpler rules using disjunction. The W3C seems love RDF and wants the world to love it. Unfortunately, the current specification is a complete piece of junk. I hope RDF dies a quick and public death."

I declare...backward chaining suits me fine! "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)."

"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."

I guess that means David W is l33t! :-)

Northrop Buys Tucana and Continues Kowari

Northrop Grumman Buys the Tucana Knowledge Server "Stunningly for a company their size, Northrop has not only agreed to support Kowari but rushed to do so. I certainly didn't expect a US federal systems integrator to "get" Open Source Software, but times have clearly changed. Their senior managers have made a legitimate effort to figure out the licensing and how to make it work within their business model. I have confidence that we can figure out a way to make it work for both the Kowari community and Northrop Grumman."

A Grumman employee? Or a Thoughtworker with inside knowledge? Building an Agile Enterprise "I have confidence that we can figure out a way to make it work for both the Kowari community and Northrop Grumman."

Update: Paul's doing the handover

Fibrous Blogging

David Wood's new blog, is where he sits down and gives us a vigorous, new article "Making the Semantic Web Viral": "The Semantic Web has not undergone the explosion of users that caused the early World Wide Web to be successful...The barrier to entry is currently substantially higher than it was in the early Web."

"The way I see it, Web links with semantics need an attribute on a hyperlink that defines the relationship between the resources...Once you have links with semantics, you need to provide a means of navigating from the existing Web to the more abstract space of RDF and back again. You can already link a Web page to another Web page, but what do you do when you want to link to a person? Representing people as email addresses or even FOAF files is weak, silly and just plain insufficient. People exist only in Meat Space and so have to be represented in Semantic Web Space by some non-trivial means. RDF & OWL already provide a great answer for this: A person object can exist that link to email addresses, FOAF and all the rest. Now we only need a way to navigate it via the Web."

I'm not sure if this is anything like what David wants but I recently came across Cocoal.icio.us. This is a nice OS X client for del.icio.us. The screenshots shows a user searching and adding metadata.

New co-Chair of SW Best Practices

"This is to inform you that as of 14 July 2004, David Wood of Tucana Technologies joins Guus Schrieber of Ibrow as co-Chair of the Semantic Web Best Practices and Deployment Working Group (SWBPD) [1]. We wish to express our thanks to David and Tucana and to Guus and Ibrow for their generous support of the Semantic Web Activity."

Fwd: W3C Announcement: David Wood, New Co-Chair of the Semantic Web Best Practices and Deployment Working Group