What’s installed on the build machine in Visual Studio Online(Team Foundation Service)?

Great question, great answers …

official	http://www.visualstudio.com/en-us/get-started/hosted-build-controller-vs#software
in detail	http://listofsoftwareontfshostedbuildserver.azurewebsites.net
inside VS2012	Avanade Extensions for VS2012
inside VS2013	Avanade Extensions for VS2013