In two words: KiTE as a template engine that uses {{mustache}} idea of minimalistic template definitions. 

Major differences: 

1. It works 40 times faster than original {{mustache}}. And 2-3 times faster than jQuery.template().
2. It has conditional sections {{? foo == "bar" }} it is a bar {{/?}} 
3. It supports custom formatters: {{born|date}} - the engine will call custom date() function for the 'born' field.

KiTE is published here:  http://code.google.com/p/kite/

You can visit  http://terrainformatica.com/kite/test-kite.htm to get a feeling of KiTE templates.

If needed I can wrap it into jQuery plugin.