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Apache CloudStack release documentation is available on the Apache CloudStack Web site. This includes the API developers guide, Admin Guide, CloudStack Nicira NVP Guide, Installation Guide, and Release Notes.
We do most of our discussion and work on the Apache CloudStack mailing lists. Specifically, developer discussions happen on the cloudstack-dev mailing list. If you're looking for user support, the cloudstack-users list is the best place to go. (You may be tempted to send mails to both lists looking for help. Avoid that temptation. It's much better etiquette to direct emails to one list only, and to use the appropriate lists.)
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