GoToSocial

GoToSocial is an ActivityPub‑based social networking server written in Go that implements the Mastodon client API, allowing users to post, follow, favourite, reply to, and share text, images, and articles within a federated environment. It offers granular visibility controls, reply restrictions, local‑only posting, RSS feeds, rich‑text formatting, theming, and custom CSS, while supporting OIDC integration and multiple federation modes for flexible deployment.

The software targets individuals and organizations that want a self‑hosted, free‑tier, open‑source alternative to existing Fediverse platforms, emphasizing safety, privacy, and the absence of recommendation algorithms or advertising. Its backend‑first design and easy‑to‑run installation aim to simplify setup and maintenance for administrators, with optional TLS, health checks, tracing, and metrics for enhanced security.

Distinctive aspects include its lightweight Go implementation, focus on security features, and compatibility with Mastodon clients despite being a separate codebase. The project is released under AGPL‑3.0, is considered stable, and is actively developed with documentation and community contributions.