While the project has several communications channels, the mailing lists are the most active and the official channels for making decisions about the project itself. "If it didn't happen on a mailing list, it didn't happen."
The project currently has three lists:
cloudstack-dev: Where discussions about development and the project itself happen. This is a high volume list.
cloudstack-users: This list is for users of CloudStack to seek and provide support. This is a moderately high volume list.
cloudstack-commits: This list is for commits to the CloudStack git repository. It's a high volume list with automated messages, probably of limited interest to anyone who is not actively developing Apache CloudStack.
Citrix supports the open source community via developer support and evangeslism. We have a number of developers and evangelists that participate actively in the open source community in Apache Cloudstack, OpenDaylight, Xen Project and XenServer. We also conduct educational activities via the Build A Cloud events held all over the world.