Compiled in september 2008 Cosmos 2.0 (the one of this page) reuse (and extend!) all the features of the old Cosmos XT 1.0 compiled in june 2005. So we must not believe that Cosmos XT 1.0 is better than Cosmos 2.0... it's the contrary.
The only plugin remaining is Cosmos 2.0 (the one of this page). The old Cosmos XT 1.0 is discontinued and not necessary to try to find anywhere.