PuSH Bot is a PubSubHubbub-to-XMPP service that I created a couple of years ago. It had been running pretty much attended for a while, but in the past couple of months I started to get a complaint or two that it was flaky. It turned out that the new App Engine pricing model was making it not fit into the free quota anymore, so by late afternoon the service would start to report errors (it's not the only unattended App Engine app that this has happened to).
I decided to dust off the code, move it to its own repository and see if it could be brought back to life. Between some basic optimizations and kicking out some (unintentionally?) abusive users, it now fits in the free quota on most days. I also took this opportunity to modernize the code a bit.
With Google Reader shared items gone, some of the initial use cases aren't there anymore (I don't want to subscribe to random blogs with it; that's what Reader is for). However, there are still plenty of other sites that support PubSubHubbub. One recent addition that I'm experimenting with is Stack Overflow. With per-tag feeds, I can now get notified via IM when someone asks a question in the two topics that I tend to answer.
