Manuals contains the documentation engine from Builder as a standalone application. Not only does it browse documentation organized by SDK but can install additional SDKs too. This is done using the same techniques Builder uses to manage your project SDKs.
It should feel very familiar if you’re already using the documentation tooling in Builder.
In the past, we would just parse all the *.devhelp2 files up-front when loading. GMarkupParseContext is fast enough that it isn’t too much overhead at start-up for a couple hundred files.
However, once you start dealing with SDKs and multiple versions of all these files the startup performance can take quite a hit. So Manuals indexes these files into SQLite using GOM and performs queries using that instead. It conveniently makes cross-referencing easy too so you can jump between SDK revisions for a particular piece of documentation.
Enjoy!