SemanticMediaWiki

SemanticMediaWiki is a MediaWiki extension.

Main purpose: Associate semantic properties with wiki pages, and various features based on it.
Repository: https://github.com/mediawiki4intranet/SemanticMediaWiki
Homepage: http://semantic-mediawiki.org, SemanticMediaWiki on mediawiki.org
License: GPLv2.0+
Created: 2006-08-22
Our rating: May be useful (3)

Status for Mediawiki4Intranet distribution:

Our improvements

Query optimizer: identical subqueries are executed only once (for example, in <q>a OR b</q> <q>c OR d <q>a OR b</q></q> the «a OR b» part will be executed only once), identical terms are removed from conjunctions/disjunctions («a AND a», «a OR a» == just a)
Conjunction-of-disjunctions execution bug: in the original SMW, «(a OR b) AND (c OR d)» query was not executed at all! (test case: {{#ask: <q>[[A::B]] OR [[C::D]]</q> <q>[[E::F]] OR [[G::H]]</q> | format=debug }}). Patch sent to github: https://github.com/SemanticMediaWiki/SemanticMediaWiki/pull/19
Negation operator support: syntax is {{#ask: [[prop::val]] !<q>...subquery...</q> }} or just {{#ask: [[prop::val]] ![[prop2::val2]] }}. Patch sent to github: https://github.com/SemanticMediaWiki/SemanticMediaWiki/pull/20
Disable forced type-named properties: in the original SMW, data type aliases also have an unpleasant side-effect: if a property name matches the alias of some data type (for example «Telephone number») — the property will have that data type forced and you cannot override it. Patch sent to github: https://github.com/SemanticMediaWiki/SemanticMediaWiki/pull/21
Automatic refresh of all pages with semantic queries on any property update — in the original SMW you have to manually refresh it every time. Of course this can lead to frequent cache flushes — even the queries that don’t use the updated property are flushed — but at least the user always gets correct query results.