@Felix+Holger: This question is very interesting - for me any my colleagues too.
Can I get this list on my own? I would document that - just give me a hint where to look in the sources (I even recently bought a new Ruby+Rails book to learn developing with Rails) ;-)

The available variables and tags are available in the {{tags}} and {{variables}} variables. You can see them in action on the Liquid for Editors page.

Nicolas: The toc tag is part of the core set of Liquid tags available in ChiliProject. lastupdate_by probably comes from the wiki extensions plugin and is thus not available in ChiliProject by default. That said, it should be rather simple to make it available using a syntax similar to {{page.lastupdate_by}}.

Chris: Most of the tags and filters come from the liquid gem. The integration is mostly in lib/chiliproject/liquid and around the textilizable method in app/helpers/application_helper.rb.

Thanks - didn't find that till now... so this is a task for #1221, too ;-)

I'll take the wiki page and the offical docs (https://github.com/Shopify/liquid/wiki) for overhauling the docs.