This code creates a simple web site that queries Wikipedia to get the edit history of a page and renders it as a "history flow" in SVG. For background see Visualising edit history of a Wikipedia page. Inspiration came from Jeff Attwood's post Mixing Oil and Water: Authorship in a Wiki World, which discusses the History Flow project.

Below is the history flow for the Wikipedia article on Phylogeny:

After grabbing the XML for a Wikipedia page the script breaks the text into lines and uses Text_Diff to compute the difference between these lines. It then creates a simple SVG diagram showing these edits. You can click on columns in the diagram to see particular revisions, and on rows to see individual contributors to Wikipedia.

To use this script make sure check the values for

$config['proxy_name']=''

$config['proxy_port']=''

in the file utils.php. If you are behind a HTTP proxy then you'll need to enter the name and port of your proxy, otherwise leave them as ''.

Apart from the fact that the SVG may take a while to render, the code is sensitive to changes in the XML returned by Wikipedia. The history of edits is recorded in the XML file returned by

http://en.wikipedia.org/wiki/Special:Export/[page title]?history

The "wiki" namespace version changes over time (it is currently 0.5, i.e. http://www.mediawiki.org/xml/export-0.5/). This is hard-coded in the file history.php, and will need to be changed if Wikipedia increments this version of the namespace. You can inspect the current namespace version here: https://en.wikipedia.org/w/index.php?title=Special:Export&action=submit