Acronym for Single System Image. It is used to differentiate between machines such as the SGIAltix and clusters like Beowulfs.
An SSI machine runs one copy of the OS, and each node can access every other nodes memory directly without doing anything special.
Also Server Side Iincludes.
A rudimental language to be used with HTML pages for inclusion of other files and/or some very basic processing, achieving a crude form of dynamic webpage generation. For very small sites, SSI can be a completely sufficient form of a ContentManagementSystem.
