The figure below shows the main components of a KMS frame. (The figure is borrowed from the Hypertext'87 proceedings.) Clicking on the menu items means following a link to another frame, or possibly the execution of a program (written in the KMS action language). There are two types of links: hierarchical links and cross-reference links. The distinction between these types of links makes you aware that when following a cross-reference link you are jumping to another part of the hyperdocument. This distinction between the types of links is supposed to make up for the lack of overview diagrams.
KMS is designed for collaboration between users. There is no separation between readers and authors, and all changes made by one user become immediately visible to all other users. KMS ignores the risk that two users may want to change the same frame at the same time. It does not want to forbid access to a frame when another user is editing that frame.
Because of the (almost strictly) hierarchical structure of KMS hyperdocuments, and the way the links are presented (separate from the frame body), KMS does not offer the "hypertext look and feel" of most other systems.