Yes i've come across that one, tho it seems to not be maintained anymore since a long time, and i had some problemes in the way i wanted to use it with IE (as usual..)
Main reason i really like jtemplates is because i am very happy with jquery and managed to wrap all of jtemplates functionality into jquery, so i can do something like $("#div").BindTemplate(jsonData, callBack);, where it will go fetch a file called "div.aspx" in a templates folder via httpGet and then apply the json data to the template, while putting the fetched template into a user-side cache. Works like a charm on a chat with thousands of simultaneous users :) ..now i just need to get rid of old Ajax.Pro and replace it with a simple asmx scriptservice so we can use jquery for the client-server communication part too. - Robert