Ascension is an .NFO file viewer that aims to display ASCII as it was meant to be seen, i.e. using antiquated code pages in a way that modern browsers and text viewers are not capable of. The program allows selection of encoding (i.e. code page number) and selection from a set of color schemes.
The irony of an .NFO reader for Mac is that the heyday of the .NFO file format appears to have been the MS-DOS era - it's hard to conceive that any of them were created with a modern Mac user in mind. But perhaps it's this niche need that makes Ascension particularly useful. As a longtime Mac user, I certainly hadn't heard of the format before, and had a hard time finding examples of art created with it. For those who, like me, are simply curious to see how this old-school ASCII art thing works, there's a free pack of sample .NFOs on the Ascension website.
Strangely, the default purple-on-purple color scheme is not available as one of the application's eight provided schemes. It begs the question a little of why the developers stopped short of providing full color customization.