A filter allowing you to insert a node wherever the InsertNode filter is available. It can be used to create macros, insert book links, create a link to a node showing its title, etc.
The complete documentation is now available at Made to Order Software:
Flexifilter is a module that allows non-coders to create their own, configurable custom filters. It is not limited to simple text replacement or regex replacement; it includes logic such as if() and while() statements, and is easily extendable by other modules. It is the best thing to hit Drupal since the potato.