Guide (Peter Brown 1986)
Guide was developed at the University of Kent on a UNIX system. In 1986 it was released as a commercial product by OWL (Office Workstation Ltd.) first for Macintosh and later for the IBM PC. Thus, it was the first hypertext system available on both systems. It is also a window-based system.
An interesting aspect of Guide is that it supports three different kinds of hypertext links:
To differentiate between the three link types, the shape of the cursor changed depending on the type of link; an asterix for a pop-up link, an arrow for a reference link, a circled cross to open an inline replacement, and a square to close an inline replacement.