
Help Viewer is a WebKit based HTML viewer for macOS aimed at displaying help files and other documentation. It is found in /System/Library/CoreServices/Help Viewer.app. The default file extension is ".help". Help index files are generated with Help Indexer. macOS applications typically use Help Viewer to display their help content, rather than a custom system.

Balloon help is a help system introduced by Apple Computer in their 1991 release of System 7.0. The name referred to the way the help text was displayed, in "speech balloons", like those containing words in a comic strip. The name has since been used by many to refer to any sort of pop-up help text.

Devhelp is a GTK/GNOME browser for API documentation; it works natively with gtk-doc.

In computing, help is a command in various command line shells such as COMMAND.COM, cmd.exe, Bash, qshell, 4DOS/4NT, Windows PowerShell, Singularity shell, Python, MATLAB and GNU Octave. It provides online information about available commands and the shell environment.

Help & Manual is a Windows-based help authoring tool published by EC Software, a company based in Austria.

HelpNDoc is a Windows-based help authoring tool published by French company IBE Software.

HelpSmith is a Windows-based help authoring tool published by Divcom Software.

Info is a software utility which forms a hypertextual, multipage documentation and help viewer working on a command line interface.

Macintosh Guide, also referred to as Apple Guide, was Apple Computer's online help and documentation system, added to the classic Mac OS in System 7.5 and intended to work alongside Balloon Help. In addition to hypertext, indexing and searching of the text, Macintosh Guide also offered a system for teaching users how to accomplish tasks in an interactive manner. However, the process of creating guides was more complicated than non-interactive help and few developers took full advantage of its power. Apple enhanced the help system with HTML-based help in Mac OS 8.5 which worked in conjunction with Macintosh Guide providing links to Macintosh Guide sequences. Macintosh Guide was not carried over into Mac OS X, which uses an HTML-based help system.

A man page is a form of software documentation usually found on a Unix or Unix-like operating system. Topics covered include computer programs, formal standards and conventions, and even abstract concepts. A user may invoke a man page by issuing the man command.

NamePros is an online community for domain name investors. Its services include forums and domain name auctions. The forums implement a freemium business model, whereby membership is free, but paid subscriptions offer additional features.