The start of the LastGraph rewrite is well underway; the backend has been moved to Django (probably out of familiarity, since I've been using it quite a bit recently), and is already fetching week lists and track lists, much to my delight.
This time around, I'm grabbing the weekly track charts, not the artist charts, and decoding and storing all of the data in a database, which is then queried to get artist statistics. This way, I'll have all that data I bothered fetching around for future use, such as the Flash-based graph viewer I am contemplating (it does exist, but has only got as far as rendering predefined graphs...).
In more interesting (visual) news, the new rendering backend has been somewhat spun off into its own project, called 'Graphication'. It's built on top of Cairo, and the idea is to eventually provide a nice API for snazzy graph creation (LastGraph will have a few more graph types in future, which is one of the reasons for doing this. Radial graphs of genres/artists/tracks, anyone?).
It already has a working wavegraph rendering module, an example output of which is above (the data is randomly generated). I'm now going to move on to the text-on-curves part, which is quite simple to do, but I'm going to try and find a way of making it less brute-force-ish, in the hope it might run a little faster.