The CircleMUD^2 dev group maintains both a dev mailing list for intra-group communication and support, as well as an announcement mailing list for release and bug notifications.

To subscribe to either of the mailing lists, simply send an email to:

dev-request@circlemudsquared.org
or
announce-request@circlemudsquared.org

With the word "subscribe" in the subject line.

Archives of both mailing lists are available online:

dev archive
announce archive

There is also a web-based interface for subscribing, unsubscribing, and changing options.