+ * [[bugs/SVG_files_not_recognized_as_images]]
+
+## Plugins
+
+These plugins are experimental. Use them at your own risk. Read the
+perldoc documentation for more details. Patches and suggestions are
+welcome.
+
+ * [mdwn_itex][] - Works with the [[`mdwn`|plugins/mdwn]] plugin to convert inline [[todo/LaTeX]]
+ expressions to [[MathML]] using `itex2MML`.
+
+ * [h1title][] - If present, use the leading level 1 Markdown header to
+ set the page title and remove it from the page body.
+
+ * [code][] - Whole file and inline code snippet [[todo/syntax highlighting]]
+ via GNU Source-highlight. The list of supported file extensions is
+ configurable. There is also some preliminary [documentation][code-doc].
+ See the [FortranWiki](http://fortranwiki.org) for examples.
+
+ * [metamail][] - a plugin for loading metadata from [[email]]-style
+ headers at top of a file (e.g., `title: Page Title` or
+ `date: November 2, 2008 11:14 EST`).
+
+ * [pandoc][] - [[ikiwiki/Markdown]] page processing via [Pandoc](http://johnmacfarlane.net/pandoc/) (a Haskell library for converting from one markup format to another). [[todo/LaTeX]] and
+ [[reStructuredText|plugins/rst]] are optional.
+
+ * [path][] - Provides path-specific template conditionals such as
+ `IS_HOMEPAGE` and `IN_DIR_SUBDIR`.
+
+ [mdwn_itex]: http://code.jblevins.org/ikiwiki/plugins.git/plain/mdwn_itex.pm
+ [h1title]: http://code.jblevins.org/ikiwiki/plugins.git/plain/h1title.pm
+ [code]: http://code.jblevins.org/ikiwiki/plugins.git/plain/code.pm
+ [code-doc]: http://code.jblevins.org/ikiwiki/plugins.git/plain/code.text
+ [metamail]: http://code.jblevins.org/ikiwiki/plugins.git/plain/metamail.pm
+ [pandoc]: http://code.jblevins.org/ikiwiki/plugins.git/plain/pandoc.pm
+ [path]: http://code.jblevins.org/ikiwiki/plugins.git/plain/path.pm
+
+
+## MathML and SVG support
+
+So far, I've made some notes on sanitizing MathML and SVG via
+htmlscrubber on the [[todo/svg]] todo item.
+
+I've also worked out some content-negotiation issues. First of all,
+one needs to modify the default templates to use the
+XHTML+MathML+SVG doctype (see e.g., this [patch][template-patch]).
+For most browsers, the content type of the pages should be
+`application/xhtml+xml`. The solution is easy if you want to
+just send `application/xhtml+xml` to everybody:
+just change the content type of `.html` files across the board.
+
+However, if you want to support browsers that don't accept
+`application/xhtml+xml` (and those that will but say they
+don't, such as IE with the MathPlayer plugin), then one
+needs a `mod_rewrite` rule like the following:
+
+ RewriteCond %{HTTP_ACCEPT} application\/xhtml\+xml [OR]
+ RewriteCond %{HTTP_USER_AGENT} (W3C.*Validator|MathPlayer)
+ RewriteRule \.html$ - [T=application/xhtml+xml]
+
+This solves the problem of MathML and inline SVG in static pages
+but some additional work is required for dynamically generated
+pages, like page previews, that are generated by `ikiwiki.cgi`.
+We need to allow `ikiwiki.cgi` to set the content type dynamically
+based on the `HTTP_CONTENT_TYPE` environment variable
+(e.g., with the following [patch][cgi-patch]). Then, the following
+rewrite rules can pass the correct content type to ikiwiki:
+
+ RewriteCond %{HTTP_ACCEPT} application\/xhtml\+xml [OR]
+ RewriteCond %{HTTP_USER_AGENT} (W3C.*Validator|MathPlayer)
+ RewriteRule ikiwiki.cgi$ - [T=application/xhtml+xml]
+
+One final critical issue is that a production-ready setup needs to
+implement some sort of on-the-fly error handling. If a user submits
+an invalid LaTeX expression or SVG code (not malicious, just invalid)
+and saves the page, then browsers like Firefox will halt processing of
+the page, preventing any further viewing or editing. A less than
+optimal solution is to force users to preview the page before saving.
+That way if someone introduces invalid XHTML then they can't save the
+page in the first place (unless they post directly to the right URL).
+
+ [template-patch]: http://xbeta.org/gitweb/?p=xbeta/ikiwiki.git;a=blobdiff;f=templates/page.tmpl;h=380ef699fa72223744eb5c1ee655fb79aa6bce5b;hp=9084ba7e11e92a10528b2ab12c9b73cf7b0f40a7;hb=416d5d1b15b94e604442e4e209a30dee4b77b684;hpb=ececf4fb8766a4ff7eff943b3ef600be81a0df49
+ [cgi-patch]: http://xbeta.org/gitweb/?p=xbeta/ikiwiki.git;a=commitdiff;h=fa538c375250ab08f396634135f7d79fce2a9d36