PocketBase

PocketBase is an open-source backend distributed as a single Go executable. It embeds an SQLite database, built-in user authentication, file storage, a REST-ish API and an admin dashboard, and can also be used as a Go framework for custom logic. It is developed largely by one maintainer (Gani Georgiev) rather than a company. The README describes it as an open source Go backend and says it is licensed under the MIT License.

As a standalone app, you download the prebuilt executable for your platform, extract the archive and run ./pocketbase serve. The prebuilt executables come with the JS VM plugin enabled by default, so they can be extended with JavaScript. As a Go framework, PocketBase is a regular Go library package, so you can add your own business logic and still end up with a single portable executable; the README asks for Go 1.27+ for that route.

The website says the authentication system handles email/password and OAuth2 sign ups with Google, Facebook, GitHub and GitLab, and that files can be stored locally or in S3 storage. The README warns that PocketBase is still under active development and that full backward compatibility is not guaranteed before reaching v1.0.0, which matters when planning upgrades.