On behalf of Cognifide I would like to donate Sling Dynamic Include (SDI) as extension to Apache Sling project.
SDI allows you to include dynamic page fragments (components) using ESI, SSI or AJAX tags, separately from the static part of the page. Actually it makes possible to cache partially dynamic pages, in declarative way and without additional development effort. You can find more information about the SDI on the github  and on Cognifide's blog . I created ticket SLING-5594  to track donation process and I'm currently preparing a code package.  https://github.com/Cognifide/Sling-Dynamic-Include  https://www.cognifide.com/our-blogs/cq/sling-dynamic-include/  https://issues.apache.org/jira/browse/SLING-5594 Thanks, Przemyslaw Pakulski