We use an open source discussion forum software to power this message board. Unfortunately, it is missing some "enterprise" functionality like AAI or LDAP backed logins. We are evaluating a solution that will eventually allow access either via LDAP or AAI - but for now we have chosen to go with a separate signup process.
As an alternative, we will enable certain other federated logins - Github, Twitter, Google and Facebook come to mind. They will show up here over time.