Debian has the slickest update feature set which allows one to upgrade over the internet. Includes intrusion alert capabilities, improved authentication and access control, and complete SSL secure web-based administration. Linux for paralell cluster computing. Based on redhat. Compiled with stackguard for enhanced security.
Nothing is auto configured.
User specifies all. Full development tools for real time. Internet appliance version available. Not for wimps. HTTP, FTP, network management tools.