muspy is an album release notification service, you give it a list of your favourite artists and it sends you a notice (by email or RSS) as soon as they have new releases.
I wrote muspy 3 years ago to scratch a personal itch -- I was spending too much time online checking if bands I'm into have something new; but was still missing many releases.
muspy was initially developed for Google App Engine, which was the hot new thing back then. In retrospect, while working with App Engine was extremely educational and a lot of fun, it wasn't a very good fit. The recent announcement on the price increase was the last straw -- I decided to re-write it in vanilla Django and to host it myself.
I'm also releasing the source code under GNU AGPL in the hope that it will be beneficial for the service and for its users.
Major changes since the previous version:
Track release groups instead of releases
This was the most frequently requested feature, there were too many duplicate releases for some artists, release groups make everything much cleaner. This change was also the reason why the new version is almost a complete rewrite.
Stars are off by default for new releases
muspy allows to star individual releases, starred releases show up on top of the sorted list of releases. This feature wasn't used by many which resulted in all releases being starred for most users. Now stars are off for new releases, if you want to star, you have to do it manually on the website. I migrated stars only for users with S \< min(R, 40) / 2, where S is the number of starred releases and R is the total number of releases for all artists you follow.
It used to take more than a week to check all artists for new releases, now the checking cycle is much shorter. Things like importing from Last.fm or adding a comma-separated list of artists should also be significantly faster.
Other than that, muspy remains pretty much the same. I migrated all the data but I encourage you to go the old site at muspy.appspot.com and to check if everything was migrated correctly. Please note that the old site's background processes are not running and it will be taken down in a month or two.
Now that muspy is free and open-source, don't hesitate to look at the code, tweak it and suggest improvements. Git and GitHub make it too damn easy!
And if you never used muspy before, give it a try!