The sample contains:

Registration for a "Project Factory" without an implementation (under a random guid) for a fake language ("Foo" in this instance). The interesting part is in Foo.pkgdef

A C# Project Template under the "Foo" project type in your vstemplate files. ProjectTemplate1.vstemplate

!Warning: The above is obviously a huge hack. Be careful not to override an existing project factory, because that can cause mayhem in Visual Studio.