Reply To: Cruise onboard communicating
It is open source, and can be found here: http://www.gitorious.org/statusnet-client
Details on how to build the source are here: http://status.net/wiki/Building_StatusNet_Desktop_from_source
The apps appear to use this http://www.appcelerator.com/products/titanium-cross-platform-application-development/ as a development platform, rather than native ObjectiveC or Java, so it might be trickier to build.