If you're heavily involved in GNOME's development, you may know all about GNOME Builder, a bespoke IDE (Integrated Development Environment) for the desktop environment in question.

What's really cool about GNOME Builder is that it blends a wide range of technologies such as GTK+, GLib, and GNOME APIs with a lot of features that are essential for IDEs such as code snippets, syntax highlighting, Git integration, etc.

Builder also boasts an extensive documentation component. As it happens, that documentation component has been extracted from GNOME Builder (by the same developer that built it in the first place), and it's now available as a standalone app.

The app in question is called (quite appropriately) Manuals. What it does is it allows developers to install, browse, and search developer documentation.

Upon launching Manuals, the app scans the host operating system, as well as flatpak runtimes, and the jhbuild installation. All the documentation is indexed in SQLite using GNOME/gom.

As it stands, only the devhelp2 format is supported, but the developer has plans to add additional formats in the future. Speaking of the future, the app's roadmap points to some nifty future features such as the indexing of manpages such as POSIX headers, Sphinx documentation support, as well as indexing online-based documentation of various sorts.

Manuals is a niche app that is capable of installing developer documentation (SDK) from Flatpak. It also boasts robust browsing and search capabilities to make the lives of those who use it a bit easier. Since Manuals is a GTK4 app, it also features decent integration with GNOME which is good for a few aspects including the app's ability to automatically change its theme mode.