+By default, pages in the wiki are written using the [[MarkDown]] format.
+Any page with a filename ending in ".mdwn" is converted from markdown to html
+by ikiwiki. Markdown understands text formatted as it would be in an email,
+and is quite smart about converting it to html. The only additional markup
+provided by ikiwiki on top of regular markdown is the [[WikiLink]] and
+[[PreprocessorDirective]].
+
+If you prefer to use some other markup language, ikiwiki allows others to
+easily be added by [[plugins]]. For example it also supports traditional
+[[plugins/WikiText]] formatted pages, pages written as pure
+[[plugins/HTML]], or pages written in [[reStructuredText|plugins/rst]]
+or [[Textile|plugins/textile]].
+
+ikiwiki also supports files of any other type, including plain text,
+images, etc. These are not converted to wiki pages, they are just copied
+unchanged by ikiwiki as it builds your wiki. So you can check in an image,
+program, or other special file and link to it from your wiki pages.
+
+## [[Blogging|blog]]
+
+You can turn any page in the wiki into a [[blog]]. Pages matching a
+specified [[PageSpec]] will be displayed as a weblog within the blog
+page. And RSS or Atom feeds can be generated to follow the blog.
+
+Ikiwiki's own [[TODO]], [[news]], and [[plugins]] pages are good examples
+of some of the flexible ways that this can be used. There is also an
+[[example_blog|examples/blog]] set up that you can copy into your own wiki.
+
+Ikiwiki can also [[plugins/aggregate]] external blogs, feeding them into
+the wiki. This can be used to create a Planet type site that aggregates
+interesting feeds.
+
+You can also mix blogging with podcasting by dropping audio files where
+they will be picked up like blog posts. This will work for any files that
+you would care to syndicate.
+
+## Valid html and [[css]]
+
+ikiwiki aims to produce
+[valid XHTML 1.0](http://validator.w3.org/check?url=referer).
+ikiwiki generates html using [[templates]], and uses [[css]], so you can
+change the look and layout of all pages in any way you would like.
+
+## [[Plugins]]
+
+Plugins can be used to add additional features to ikiwiki. The interface
+is quite flexible, allowing plugins to implement additional markup
+languages, register [[PreProcessorDirective]]s, hook into [[CGI]] mode,
+and more. Most of ikiwiki's features are actually provided by plugins.
+Ikiwiki's backend RCS support is also pluggable, so support for new
+revision control systems can be added to ikiwiki.
+
+## [[todo/utf8]]
+
+After rather a lot of fiddling, we think that ikiwiki correctly and fully
+supports utf8 everywhere.
+
+## Other features
+
+The above are the core design goals and features of ikiwiki, but on that
+foundation a lot of other important features are added. Here is an
+incomplete list of some of them.
+
+### [[Tags]]
+
+You can tag pages and use these tags in various ways. Tags will show
+up in the ways you'd expect, like at the bottom of pages, in blogs, and
+in RSS and Atom feeds.
+
+### [[SubPages|SubPage]]
+
+Arbitrarily deep hierarchies of pages with fairly simple and useful
+[[SubPage/LinkingRules]]
+
+### [[BackLinks]]
+
+Automatically included on pages. Rather faster than eg MoinMoin and
+always there to help with navigation.
+
+### Smart merging and conflict resolution in your web browser
+
+Since it uses a real RCS, ikiwiki takes advantage of its smart merging to
+avoid any conflicts when two people edit different parts of the same page
+at the same time. No annoying warnings about other editors, or locking,
+etc, instead the other person's changes will be automatically merged with
+yours when you commit.
+
+In the rare cases where automatic merging fails due to the same part of a
+page being concurrently edited, regular commit conflict markers are
+shown in the file to resolve the conflict, so if you're already familiar
+with that there's no new commit marker syntax to learn.
+
+### [[RecentChanges]], editing pages in a web browser
+
+Nearly the definition of a wiki, although perhaps ikiwiki challenges how
+much of that web gunk a wiki really needs. These features are optional
+and can be enabled by enabling [[CGI]].
+
+### User registration
+
+Can optionally be configured to allow only registered users to edit
+pages.
+
+User registration can be done using a web form, or ikiwiki can be
+configured to accept users authenticated with OpenID, or HTTP basic
+authentication, or other methods implemented via plugins.
+
+### Discussion pages
+
+Thanks to subpages, every page can easily and automatically have a
+/Discussion subpage. By default, these links are included in the
+[[templates]] for each page.
+
+### Edit controls
+
+Wiki admins can [[lock_pages|page_locking]] so that only other admins can
+edit them. Or a wiki can be set up to allow anyone to edit Discussion
+pages, but only registered users to edit other pages. These are just two
+possibilities, since page edit controls can be changed via plugins.
+
+### [[PageHistory]]
+
+Well, sorta. Rather than implementing YA history browser, it can link to
+[[ViewVC]] or the like to browse the history of a wiki page.
+
+### Full text search
+
+ikiwiki can use the [[HyperEstraier]] search engine to add powerful
+full text search capabilities to your wiki.
+
+### Commit mails
+
+ikiwiki can be configured to send you commit mails with diffs of changes
+to selected pages.
+
+### [[w3mmode]]
+
+Can be set up so that w3m can be used to browse a wiki and edit pages
+without using a web server.