The Short Links plugin (previously called Wiki Links plugin) is a renderer plugin which allows to easily create links from one post to another.
This is especially useful for forums or manual in which you probably do not allow plain html links in the form of
<a href="destination">link title</a>.
In b2evolution 6.7.0, the Short Links Plugin provides a toolbar button allowing to quickly select the destination Post in a modal window. (This leverages the API?.)