Lots of Amiga documentation was in the AmigaGuide format. These are simple ASCII documents with some rudimentary markup to turn them into hypertext, working something like TeXInfo manuals. Think more like a markdown-enabled Gopher than the web though: you can link out to an image, video, or any other media (you could once you had AmigaOS 3, anyway) but you can’t display it inline.
Unfortunately choices for modern readers are somewhat limited. Many links are only now found on the Internet Archive, and many of those don’t go to downloads you can actually download. I found a link to an old grotag binary, but it was PowerPC-only.
…and it was on Sourceforge, so I cloned the project and updated the build. I haven’t created a new package yet, but it runs well enough out of Idea. I need to work out how you package Java Swing apps, then do that. It’ll be worth fixing a couple of deprecations, putting assets like the CSS file in the JAR, and maybe learning enough JavaFX to port the UI:
To use it, alongside your Guide file you also need a grotag.xml that maps Amiga volume links onto local filesystem paths, so that grotag can find nodes linked to other files. There’s an example of one in the git repo.