!!! Introduction
It's common for people to use a wiki and some discipline to replace a more complex application. They can add some plugins to make it easier.

It would be awesome to be able to program extensions of a wiki inside the wiki:
* integrated revision control
* low barrier to entry
* programming on the web

!!! Related notions
!! Existing plugin mechanisms
! Confluence plugins
The Confluence wiki allows for a lot of [different plugin types|http://confluence.atlassian.com/display/CONFDEV/Confluence+Plugin+Module+Types]
! JSPWiki plugins

!! Scott's wikitools
Scott just started some work on wiki extensions that allow to access the wiki from outside and that make use of templates [Wiki Tools]

!! Databases

Most applications need to store data and often use a database. It's common to store large amounts of data on a wiki with a repetitive text format. This is in effect a primitive type of database that tends to mix data and its presentation.
Plugins can be used to allow access to a database from a wiki page ([Database and Wiki])