cdent

Hello. I’m the developer the MovableType PurpleNumbers plugin. I’m frustrated with MovableType’s migration to corporate-hood and remembered WordPress. If I move I’m likely to try porting all the functionality of the plugin to WordPress.
What makes the plugin different from a simple regular expression parser that adds id attributes and purple hrefs is that the content is maintain in a special form (PurpleWiki wikitext) that can be parsed to a tree of nodes by the PurpleWiki libraries. Anytime a node is found without a purple number, one can be added and saved.
Therefore, content that tends to change, such as a blog page that updates, or a wiki page, is kept well purpled, even when content is reordered.
There’s a great deal of information about purple numbers in the purple category on my blog. If you have any questions please feel free to leave a comment there or email me.
To note some things from the discussion above:

• The BlueOxen and Glacial Erratics implementation of the plugin are the same. I’m one of the primary authors of PurpleWiki and implemented the MovableType plugin to see if it was possible. Once I determined it was, I then adjusted the purple numbers implementation to allow transclusion between the blog and the wiki. There’s work in progress now that will allow transclusion between any blog and any wiki, along with any other content that has been numbered in the purple way.
• IDs on the front page. If the ids (we call them NIDs) are being generated from a common sequence rather than per page, it is possible to put the same nids on the front page as the archive page, and as the link under both have the URL of the archive page. This ensures that the NID always points to the permanent location of the content, even if it is being displayed somewhere else.
• NIDs should really be generated from a sequence rather than per page. It makes all the fun with transclusion and the like possible.
• XML and XLink would be the way to go if there were sufficient browser support and a good way to create the docs.
• In the PurpleWiki parser, when entering a pre section, each section separate by a blank line gets a purple number. This is in part because of the system using wikitext, which is not going to be case in all implementations.
• I wrote a quick hack to put purplenumbers on any html page that can run javascript. It’s not ideal because the numbers are ordered from top to bottom, not resistant to change in the document, and only unique for that single page. But it is still fun. Get more info on this.