Author of Circus here.

Major differences:

* Circus uses ZeroMQ, Supervisor uses XML-RPC. * Circus is Python 3 compatible, Supervisor is Python 2 only * Circus will let you manage sockets - see http://circus.readthedocs.org/en/latest/for-ops/sockets/

Thanks for the clarifications. Just for the record it seems that Supervisor will roll out Python 3 support soon https://github.com/Supervisor/supervisor/issues/110. It's good to have it here and now though.

That's great to see Supervisor is moving forward on the Python 3 support.

Scott is actually the person who ported Circus to Python 3, so double kudos for him.

When I last compared them, circus looked more specific to managing something like wsgi workers while supervisord looked a little more "general-purpose".

This was probably a wrong or overly simplified conclusion, but I know supervisor and it hasn't let me down yet - so for now I see no compelling reason to switch. Maybe it's one of those "you just have to try it" moments? :)

Supervisor is solid and mature, that's for sure. If not for the sockets feature, I would say that you would want to move to Circus if:

- you need python 3 - you have a complex start/stop sequence where you need to add some custom code - you manage many servers and want to quickly jump from one to another in the same web dashboard / CLI.

Otherwise, they both provide roughly the same things I'd say

I watched a 60 minute talk from Tarek Ziadé a few months ago in EuroPython 2013 which was very interesting. His point regarding the missing features that made them launch project Circus were realtime stdout/stderr, realtime stats, powerful web console, remote, clustering and scalable.

You can check out the slides here: http://blog.ziade.org/slides/pyconireland2012/