- Alternative OSs on the Net - A list of operating systems and OS link sites.
- A Catalog of Operating Systems - Classified, alphabetic listing of most operating systems, past and present, distributed commercially or reported in English-language literature, platform oriented. From Computer Science 258, West Virginia University.
- Microcomputer Operating Systems - Some 70 OSs that run on microcomputers, PCs. User interfaces in earlier systems are command-line, character-oriented; later systems are mostly GUI-based. List, with brief descriptions, no links. From West Virginia University.
- Open Source Ring - Alphabetized list of many links, OSs, projects.
- Paul Hsieh OS Page - Loosely categorized list of about 100 links to developer resources for creating OSs, emulators, alternative OSs.
