We made some good progress on KnockOff [1,2] recently. It is currently the fastest library in our micro benchmarks [3] despite having a DOM-based compiler with the associated security advantages. Matt has started work on the PHP port before going on vacation, but I expect that we'll have a PHP runtime next week as well. The runtime code is still small at 337 lines.
Cheers,
Gabriel
[1]: https://www.mediawiki.org/wiki/Requests_for_comment/HTML_templating_library/... [2]: https://github.com/gwicke/knockoff [3]: https://www.mediawiki.org/wiki/Requests_for_comment/HTML_templating_library#...