ManOpen is a utility for NeXTSTEP and Mac OS X created by Carl Lindberg that can display Unix man pages in a graphical environment instead of a terminal emulator such as Terminal.

[1] Man pages are included in the program; it has a Recents menu, where users can view recently opened man pages, a Section selector to jump to a section of the manual, and a Find function that can search for text in the manual.

[1] Included with the application is a command line utility called openman that will open invoked man pages in ManOpen.

[2] Internally ManOpen does not directly view the man page but runs it though Harald Schlangmann's cat2html or cat2rtf into HTML or RTF for viewing.

[3] In their Mac OS X Version 10.1 Black Book, author Mark R. Bell and system administrator Debrah D. Suggs commented positively on ManOpen usefulness, and described it as "a great utility".