AFAIK GNOME and KDE's help systems have the ability to view info files and there is also the tkinfo viewer i mentioned.
However note that the "source documentation system" i refer to is texinfo, not info. Texinfo is a preprocessor and documentation language (think docbook) for manuals that produces a bunch of formats, one of them being info, a text-only hypertext format (which was one of the earliest hypertext formats AFAICT). GNU info is a viewer for that format, but there are others, however all of them just view info files and have its inherent limitations (e.g. preformatted text, links using a rigid syntax, etc) - though also they have benefits such as support for topic keywords, indices, etc.
Texinfo can also be converted to other formats like PDF (through tex - i guess the initial version generated only tex and info output, thus the name texinfo) and HTML. So you wont be using texinfo to view info as PDF files, but you'd be using it to generate PDF (via tex).
I guess the "texinfo" and "info" names can be confusing and make people think that they are the same thing - the fact that AFAIK texinfo is the only info file generator (and that GNU info is called just "info" which is the same as the file format name) doesn't help :-P.
However note that the "source documentation system" i refer to is texinfo, not info. Texinfo is a preprocessor and documentation language (think docbook) for manuals that produces a bunch of formats, one of them being info, a text-only hypertext format (which was one of the earliest hypertext formats AFAICT). GNU info is a viewer for that format, but there are others, however all of them just view info files and have its inherent limitations (e.g. preformatted text, links using a rigid syntax, etc) - though also they have benefits such as support for topic keywords, indices, etc.
Texinfo can also be converted to other formats like PDF (through tex - i guess the initial version generated only tex and info output, thus the name texinfo) and HTML. So you wont be using texinfo to view info as PDF files, but you'd be using it to generate PDF (via tex).
I guess the "texinfo" and "info" names can be confusing and make people think that they are the same thing - the fact that AFAIK texinfo is the only info file generator (and that GNU info is called just "info" which is the same as the file format name) doesn't help :-P.