* [[pageindexes]]
* Wiki stats, such as the total number of pages, total number of links, most linked to pages, etc, etc.
* wiki info page, giving the ikiwiki version etc
+* would it be useful to reimplement the hyperestradier search integration as a plugin?
+* Support [[RecentChanges]] as a regular page containing a plugin that updates each time there is a change, and statically builds the recent changes list. (Would this be too expensive/inflexible? There might be other ways to do it as a plugin, like making all links to RecentChanges link to the cgi and have the cgi render it on demand.)
* etc
Another, separate plugin system that already (mostly) exists in ikiwiki is the RCS backend, which allows writing modules to drive other RCS systems than subversion.
Since preprocessing happens before htmlization but after a page is loaded and linkified, it should be possible to use it to create something like a link map or lists, or a page index. Page inlining and rss generation is already done via preprocessor directives and seems a natureal as a plugin too.
-Note that things like a link map or a broken link list page would need to be updated whenever a set (or all) pages change; the %inlinepages hash already allows for pages to register this, although it might need to be renamed.
+Note that things like a link map or a broken link list page would need to
+be updated whenever a set (or all) pages change; the %depends hash
+already allows for pages to register this, although there could be some
+strange behavior if mixing multiple directives some of which exclude pages
+that others might want to include.
I need to look at the full range of things that other wikis use their plugin systems for, but preprocessor directives as plugins certianly seems useful, even if it's not a complete solution.