[[!meta title="Jason Blevins"]]
-I'm currently hosting a private ikiwiki for keeping research notes
-which, with some patches and a (currently unreleased) plugin, will
-convert inline LaTeX expressions to MathML. I'm working towards a
-patchset and instructions for others to do the same.
-
-There is one thing that needs to be decided first: whether or not to
-include [[sanitization|todo/svg]] of MathML in htmlscrubber (and while
-we're at it, why not SVG).
-
-My (also MathML-enabled) homepage: <http://jblevins.org/> (still using
-Blosxom...maybe one day I'll convert it to ikiwiki...)
-
-Current issues of interest:
-
- * [[bugs/recentchanges_feed_links]]
- * [[bugs/HTML_inlined_into_Atom_not_necessarily_well-formed]]
- * [[plugins/toc/discussion]]
- * [[todo/BibTeX]]
- * [[todo/svg]]
- * [[todo/Option_to_make_title_an_h1?]]
+I am a former Ikiwiki user who wrote several plugins and patches
+related to MathML, [[SVG|todo/svg]], and [[todo/syntax highlighting]].
+Some related links and notes are archived below.
+
+Homepage: <http://jblevins.org/>
+
+## Plugins
+
+The following [plugins](http://jblevins.org/projects/ikiwiki/)
+are no longer maintained, but please feel free to use, modify, and
+redistribute them. Read the corresponding perldoc documentation for
+more details.
+
+ * [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.
+
+ * [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://jblevins.org/git/ikiwiki/plugins.git/plain/mdwn_itex.pm
+ [h1title]: http://jblevins.org/git/ikiwiki/plugins.git/plain/h1title.pm
+ [code]: http://jblevins.org/projects/ikiwiki/code
+ [metamail]: http://jblevins.org/git/ikiwiki/plugins.git/plain/metamail.pm
+ [pandoc]: http://jblevins.org/git/ikiwiki/plugins.git/plain/pandoc.pm
+ [path]: http://jblevins.org/git/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://jblevins.org/git/ikiwiki.git/commit/?h=xbeta&id=416d5d1b15b94e604442e4e209a30dee4b77b684
+ [cgi-patch]: http://jblevins.org/git/ikiwiki.git/commit/?id=fa538c375250ab08f396634135f7d79fce2a9d36