The last time I checked out KnockoutJS (which was quite a while back), the templating syntax used was for a jQuery plugin (jQuery.tmpl) that was no longer going to be supported as part of the core jQuery plugins. The jQuery team dropped it for reasons unknown (as far as I can tell) in favor of a new templating engine, which has yet to materialize AFAIK.
jQuery.tmpl got moved over to gitHub, and it's since been abandoned. https://github.com/jquery/jquery-tmpl
But if you want to fork the project and continue improving it, you can. Hooray for open source!