Hollo

Hollo is a headless, federated microblogging server designed for single-user personal instances. It implements ActivityPub and a Mastodon-compatible REST API so existing Mastodon clients can interact with a Hollo instance.

Key Features

• Federated single-user microblogging focused on personal journals, notes, and microblogs
• Mastodon-compatible REST API surface so most Mastodon clients can be used as frontends
• Implements ActivityPub for federation with other fediverse software
• Headless design (no built-in web UI); clients render and interact with posts
• Supports CommonMark (Markdown) and very long posts (up to 10,000 characters)
• Misskey-style quotes and emoji reactions compatibility for broader fediverse feature parity
• Multiple accounts can be hosted on a single instance with per-account profiles and settings
• Built on the Fedify ActivityPub framework and provided with Docker deployment options

Use Cases

• Host a personal, federated microblog or public journal while retaining full control of data
• Use existing Mastodon-compatible desktop or mobile clients to manage posts and followers
• Create a lightweight single-user presence on the fediverse without running a full multi-user server

Limitations and Considerations

• Hollo is headless and does not provide a native web UI; a compatible Mastodon client is required for full interaction
• Some client features or third-party integrations may vary in behavior compared to full Mastodon servers
• Intended for personal/single-user use; not optimized as a replacement for full multi-user fediverse instances

Hollo provides a lightweight, standards-based way to run a personal presence on the fediverse using familiar Mastodon clients. It is suitable for users who want a simple, federated microblogging setup without a full multi-user server stack.