There are compatibility problems with Atmosphere and Trilogy when using them with DP 5.13. The plugins will show up within the sequencer, but will crash Digital Performer. 

This problem affects Power PC-based and Intel-based Mac computers running OS X Leopard. 

Because Atmosphere and Trilogy use a third-party engine that is no longer updatable, users will not be able to use Atmosphere and Trilogy with DP 5.13 and presumably all of the subsequent DP updates/upgrades. 

The successors to both plugins are based on our in-house STEAM Engine, and eliminate these kinds of support problems. Omnisphere, the successor to Atmosphere, was released on September 15, 2008, and is available now. Trilian, the successor to Trilogy, was released on October 26th, 2009.