State of Redland RDF Libraries 2008-02

Redland was born 2000-08. Happy 7.5th birthday!

This is a review of 2007 (roughly) since I reported in the State of Redland 2007-02 on 2007-02-18. It covers:

(This is on the web at

1. Redland Users

Redland is made available by several Linux, Unix and other open source projects such as:

and the libraries are also used inside other applications and services such as, for example:

2. State of the Packages

My summary of the high-level state of the packages is:

Raptor syntax parsing and serializing: libraptor
Mature. The API is growing a little since some internal parts (SAX2 API) are getting pushed into the public API. There are also some new features and syntaxes being added, portability fixes and more rarely, actual bug fixes.
Rasqal query parsing, executing: librasqal
Under development. The current API is unstable and being deliberately broken in the next release. The query engine is not complete enough to execute SPARQL and that is still the priority for 1.0.
Redland RDF API and triple stores: librdf
Mature. Some API change is happening and the storages are getting improvements. Mostly updates from Raptor and Rasqal plus bug fixes.
Language Bindings to Perl, PHP, Python and Ruby
Mature. Removed the C#, Java and Tcl bindings in 2007 as promised since I was not going to maintain them.

3. Development

In 2007, each of the packages has seen the following releases and major changes:

Raptor 1.4.15 - 1.4.16 (2 releases)
  • GRDDL support was completed and passed the test cases.
  • Improved XML and URI error handling
  • Updated Turtle parser for Turtle 2007-09-11
  • Added a TRiG parser
  • Many low-memory situation improvements
Rasqal 0.9.14 - 0.9.15 (2 releases)
  • Updated the SPARQL syntax support to match the W3C Recommendation.
  • Query engine supports all SPARQL datatypes and evaluation rules.
  • Added LAQRS syntax extensions
  • Many low-memory situation improvements
Redland 1.0.6 - 1.0.7 (2 releases)
  • A new transactions API was added implemented for MySQL and SQLite storages
  • Added a optional modular storage configuration to load storage modules on demand
  • A new query results formatter class was added
  • Many low-memory and resource allocation failure improvements
  • Many bug fixes
Language Bindings - (2 releases)
  • Removed Tcl, Java and C# bindings as promised
  • Many updates to the Python and Ruby Bindings
  • Many bug fixes

In 2007 Lauri Aalto was a new committer and made a lot of changes to the libraries in the areas of low-memory and handling resource allocation failures, mentioned above plus portability fixes for non-gcc compilers and Win32 as well as other bug fixes and improvements.

The redland mailing lists are now (early 2008) archived by and The Mail Archive. You can read them on their web sites at:

4. Challenges

The main challenge continues to be to make the project more scalable. Although I package the source code, I only really deal with Debian binary packages since as can be seen above, there are others working on distribution-specific packages, which is good.

The loss of SourceForge's compile farm was tragic since it means there is no automated way to test cross-platform compatibility.

I noticed that although 2007 had 9 releases, the previous year there were 15. This is mainly a consequence of me being busier and not developing code as part of my day job. Less releases is not necessarily bad as the packages mature but it can mean a long time to get out bug fixes.

My main goal to deal with these could be summarised as:

5. Tasks

5.1 General tasks

More of a wishlist than an ordered list

DRY = Don't Repeat Yourself

5.2 Pending stuff

There are several tasks already in progress either sitting in a patch, in Subversion or underway separately.

5.3 Raptor tasks

5.4 Rasqal tasks

5.5 Redland librdf tasks

5.6 Bindings tasks

6. Future Ideas

6.1 New Version Control System

This is the same as last year's New Version Control System idea and although it is not urgent, I'm favouring GIT right now with the main issue that it's got a steep learning curve compared to anything else.

6.2 Raptor Version 2

This break-the-binary-API I also discussed last year in Raptor Version 2 I can see being started once the focus on Rasqal 1.0 is over which should happen in 2008. There are several cleanups that need to be done.

7. Changes

In order to encourage more help with Redland, I'm proposing this:

Five good patches get you commit access.
(after Brian Aker but I'm slightly more cautious)

Plus I have started a Redland development blog ...

Thanks for reading.

Dave Beckett,
California, USA, 2008-02-18