echo 'Hi there! Have a [hyperlink](https://www.gnu.org/software/groff/manual/groff.html).' | lowdown -st man | groff -man -Thtml
So if I set MANROFFOPT=-rU1 in the environment, I can get clickable links in man… if the man page author included them that way in the first place. I'm not sure how common that is in the wild, but grepping the ones on my system, I find firejail(1) contains a link to a GitHub issue embedded in that way, and it does indeed work when I hit ^O^N to seek to it and then C-mouse1—though the mouse gesture I have Alacritty using for links doesn't seem to work through tmux (there might be a way involving twiddling the tmux terminal-features setting, but I ran out of steam before trying this), and I didn't see a great way to get either grotty or Alacritty to style them on display instead of having them blend into the surrounding text, so it's still kind of scuffed in practice. (Though I bet the cool kids have moved on from Alacritty by now?) less displays the link target in the status line when you use the navigation commands, so it's not inaccessible, but for opening selected links directly from less with the ^O^O gesture rather than leaning on terminal support, it looks like you need to explicitly set the LESS_OSC8_ANY and/or LESS_OSC8_‹scheme› environment variable to a shell command that outputs a shell command pattern to substitute the link into; if I set LESS_OSC8_ANY='echo xdg-open %o' then it passes it to my Firefox. I wonder if they'd take a patch (or if any existing distributions patch it) to use that as the default?
That was a fun little rabbit hole to go down, thank you.
… wow, hang on, I just checked for Bash, and it has an Info file but it says it's just an intro and the manual page is the definitive version‽ That's… hah. There must be some timeline jank around that; ambiguous NIH vibes around Info aside, I wouldn't have expected it from an actual GNU program! Did Bash show up before Info existed?
.Lk https://dotat.at/ "Tony Finch’s web site"
A man page source isn't a binary format, so your statement that they're "plain text" is technically correct. (The same is also true of TeX and LaTeX files, and even PostScript if you want to stretch the definition of "plain text" until it snaps.) But the renderer is groff or (legacy) troff with the `an` macro set. less(1) (or, originally, more(1)) is just the pager that consumed the former's output (if the output format is ASCII, which is one of many) and handled paging on the terminal for the convenience of the user.
In my old Sun workstation (and even early Linux desktop) days, I rarely used man(1) in the terminal because 1/terminals were usually too small and weren't usefully resizable like they are today, and 2/unadorned monospaced fonts don't look nearly as nice as properly typeset pages do. (Color terminals were just coming on the horizon, and text could only be emboldened, not italicized.) Instead, I typically used xman whenever I could. The best way I can describe xman is as if you were rendering man pages into PDFs and viewing them in Preview on the Mac. Man pages were much more comfortable to read that way.