What is the difference between Gio and Gomobile?

Go Mobile produces either standalone programs (gomobile build) or libraries suitable for calling from Java or Objective-C/Swift (gomobile bind).

gomobile build is similar to using the gioui.org/app package and the gioui.org/cmd/gogio tool to produce an Android or iOS app. The difference is the abstraction level: gomobile build programs have access to a raw OpenGL ES context while the Gio app package exposes a higher level drawing interface. Gomobile programs also don’t have any GUI packages available.

gomobile bind exports a set of Go packages for convenient access from Java or Objective-C/Swift code. There is no counterpart in Gio, and could be used for interfacing with native code from Gio programs.

Why Sourcehut?

Hosting Gio on Sourcehut is an experiment just as Gio itself is.

The most important feature of Sourcehut is that email contributions are first class citizens. Email has many problems, but it is permissionless, ubiquitous and decentralized. For example, people banned from GitHub can contribute patches, use the mailing list and file issues if they can send and receive email.

Second, Sourcehut encourages using Git in a more decentralized way. There is a canonical Gio repository, but contributors can work on their changes in ways that suit them. For example, local clones for smaller changes or pushing to a Git host of their choice for larger changes. The Sourcehut author wrote a blog post about how GitHub changed the meaning of forks and pull requests to be more self-serving and centralized.

Finally, the code for Sourcehut itself is open source, keeping it honest by the threat of self-hosting or even a complete fork. Project owners pay for hosting, lowering the incentive to extract indirect value from users and keeps the feature set focused on its projects.

Note that even ignoring the above arguments, there is not a clear alternative. For example, the Go project itself supports GitHub contributions, but only as a bridge to its preferred code review tool Gerrit.