PlaneText, developed in the MCC Software Technology Program (STP), is a very recent addition to the family of general hypertext systems. (It is perhaps too early to say, however, how PlaneText will rank in the world of hypertext, since it will only be publicaly available from the participant companies in the MCC/Software Technology Program. For more information, call Bill Stotesbery at MCC (512) 343-0978.) PlaneText is based on the Unix file system and the Sun SunView window manager. Each node is a Unix file. Links appear as names in curly brackets {} whose display can be turned on and off. Links are implemented as pointers saved in separate files, so that the linked files themselves are not changed by creating hypertext references between them. This design allows for the smooth integration of hyertext into the rest of the Unix-based computational environment, including such tools as Mail and News. It allows for the hypertext annotation of standard source code files. In addition, the Unix file directory system serves as a "free" mechanism for creating hierarchical structures among nodes. (The use of an existing tree-structuring mechanism limits any hypertext system to only being able to handle a single hierarchical structure. Single hierarchical organizations may be too limited for some advanced applications. (Conklin, 1987)