Ruby on Rails and Leopard (Server)
Internet and Web
Leopard Server also features administration for either Apache 2.2 or 1.3, MySQL 5 with Apache/MySQL/PHP integration, JBoss 4, and Tomcat 5 for hosting EJB 3.0 and J2EE 1.4-compliant enterprise applications, and Ruby on Rails with Mongrel for simplified development and deployment of web-based applications.
Mongrel on server only ? No big deal, I 'm just happy that OS X Server decided to ship the new kid on the block instead of relying on more mature but less exciting/performant solutions.