Utilities differ from applications mostly in terms of size, complexity and function. For example, word processors, spreadsheet programs, and database applications are considered applications because they are large programs that perform a variety of functions not directly related to managing computer resources.

Utilities are sometimes installed as memory-resident programs. On DOS systems, such utilities are called TSRs.

Yahoo!'s system utilities page
Yahoo!'s directory of system utilities.

PC diagnostic cards and software
This page, from Data Depot Inc., provides links to PC diagnostic test and utility products and free utility software for IBM PC compatibles. In addition, there are links to reseller information, on-line ordering, events schedule, and news and press releases.