\TeXHelp is an online \TeX handbook with simple hypertext features. It comes as a single diskette and a short booklet (28 pages including installation instructions). The MS-DOS version needs an IBM-compatible PC with version 3.0 (or a more recent version) of MS-DOS, 512 kilobytes of free memory, and approximately one megabyte of hard disk space.

\TeXHelp provides information about \TeX, \LaTeX, and AMS-TeX. Guided tours are provided for novices, and a wide variety of entries provide more detailed information, ranging from short definitions to substantial descriptions. Individual entries may be accessed from an alphabetical index, by typing the entry name, or by following a cross-reference.

The screen design is helpful and gives useful feedback (for example, how many lines of the current entry are above and below the currently visible section, and whether an entry refers to \LaTeX or AMS-TeX). Cross-references are shown in a different color. Navigation through the entries is generally by single keystrokes (for example, “i” to summon the index and “?” to see a short explanation of a highlighted term). Simple facilities are available for backtracking and for showing a list of all entries previously visited.

A few minutes of experimenting and an occasional reference to the paper handbook were all I needed to find my way around the information, and I soon found that I could locate information more easily via this program than I could in my well-worn books. The big disadvantage of \TeXHelp, however, is the relatively small number of examples and, particularly, the lack of example output. \TeXHelp only shows the \TeX source code, not the corresponding output. If your PC also runs \TeX and a \TeX previewer, TeXHelp’s View facility provides some limited viewing of example output.

Overall, I felt that \TeXHelp would be extremely useful in an environment where I could run it in one window as a quick reminder, while editing, running, and previewing \TeX in other windows. In a limited MS-DOS environment with no View facility available, it is less attractive.