You could have downloaded Manpager 1.0.1 for Mac from our application library for free. This free software for Mac OS X was originally developed by Tycho Softworks. The software lies within Developer Tools, more precisely Help.
From the developer:
Manpager is a simple application that lets you search for and view system manual pages formatted for normal output. This application is written in C++ using Qt. The Manpage viewer also lets you search for content within manual pages using the F3 key. Probably the closest equivalent is something like xman, but this offers a more complete and modern user interface as well as the ability to actively search for pages.
You may want to check out more Mac applications, such as STKXoptimizer or Tig, which might be related to Manpager.