This monograph provides information about public domain and user-supported software for IBM compatible personal computers. The Personal Computer Software Interest Group (PC-SIG) has developed this software directory for people wanting to order software from, or submit software to, the PC-SIG Library. Six sections detail: an introduction to public domain and user-supported software; an introduction to the commands needed to run programs on the IBM Disk Operating System (DOS); program descriptions; contents of available disks; indexes; and how to order disks and add programs to the PC-SIG Library. Glossary, program order forms, and software submission forms are included.