Previously called SKADS, then later called eDirectory. NDS 8 refers to the newest major revision of Novell Directory Services. NDS 8 was rewritten sizeably--the old version used essentially flat files (well, linked list files) to store directory information, and NDS 8 has a full-fledged database beneath it, so it's much more scalable than previous NDS versions. Novell has demostrated up to 1 billion objects in the directory. Cool.

NDS is neat stuff, and everyone should use it.