EasyTimeline by Erik Zachte is an extension for creating graphical timelines with clickable links. WikiHiero by Guillaume 'Aoineko' Blanchard is for rendering hieroglyphs. Both are now enabled on all Wikimedia wikis.
As per our earlier extension syntax vote, EasyTimeline uses the <timeline> syntax, WikiHiero uses the <hiero> syntax.
You can read more about them here: http://test.wikipedia.org/wiki/EasyTimeline http://test.wikipedia.org/wiki/WikiHiero
To my knowledge, MediaWiki is the only wiki software which supports such functionality. It should make our wikis interesting even in the highest academic circles.
Although EasyTimeline can generate SVG output, only PNG output is currently supported. In the future, we hope to offer SVG as a user preference.
Regards,
Erik