Notable events in software development included a new release of MediaWiki software last week, while work progresses on new features including one to help identify reliable versions of Wikipedia articles.

Last Monday, developer Brion Vibber announced the official release of MediaWiki 1.4.0 in a stable version. As is usual with MediaWiki development, Wikipedia and other Wikimedia Foundation projects had already been using this upgrade in a beta version a couple of months ahead of the official release.

Meanwhile, preparations continue for the next software version, to which Wikipedia will be upgraded in the near future. Vibber estimated that implementations of new features might still be considered for inclusion in MediaWiki 1.5 if ready within the next month. At some point soon, however, the development of version 1.5 will start focusing strictly on fixing bugs to prepare for beta and eventual release.

With respect to the upcoming schedule, Vibber has indicated that MediaWiki tends to have two or three major version releases per year. While there is no fixed deadline, six-month intervals could be a reasonable estimate. Considering that Wikipedia was moved to the MediaWiki 1.4 beta in December, a rough guess would put the transition to a beta of 1.5 around June, although many factors could still affect the timing of the upgrade.

One change that will definitely be included in MediaWiki 1.5 is a major revision of the database scheme, which will include giving the latest revision of a page its own unique identifying record. Among other things, this will make it possible to create links to the current version of an article (or diffs from that version) and still have these point to the same version after subsequent edits have been made.

In addition, Vibber issued a reminder that the databases for separate Wikimedia projects are independent of each other, a consideration that will affect plans for the server cluster. He said, "It's very likely that at some point we'll want to split out some of the larger wikis to separate master servers".

Also likely to be included MediaWiki 1.5 is the first implementation of a feature for use in rating or validating articles, written by Magnus Manske. Based on Manske's post to the Wikipedia mailing list on 18 March, the feature has been rewritten "to a point where all essential functions work", and now needs to be put through testing. People interested in generating a stable, reviewed version of Wikipedia greeted the announcement with enthusiasm. As mav commented, "Wikipedia 1.0 is starting to look less and less like vaporware."

In its preliminary stages, however, such a feature is likely to remain somewhat in the background. Besides the issue of whether and how it works in a purely technical sense, a rating system would benefit from testing in social terms, by seeing how Wikipedia contributors interact with it. As a result, the initial use of an article rating feature will probably be purely for gathering data, and evaluating whether the end product actually makes sense.