Hadn't heard of this one before. There isn't a readme and the site seems to have been taken over. But from what I can tell based on the examples, it has a yaml based scheduler and does some pretty nifty things like IRC notifications.
riko doesn't have a scheduler (although the original pipe2py has a json based one). However, I do plan to integrate with Airflow/Oozie/Luigi [1-3] in the future to make it easier to design workflows.
The notification system reminds me of Huggin [4]. Since riko is twisted based, it should be fairly straightforward to implement something similar for IRC/IMAP/FTP/etc.
[1] https://github.com/miyagawa/plagger