GoToSocial

GoToSocial provides a lightweight, customizable, and safety-focused entryway into the Fediverse.

It is server software, designed as a to support small or single-user instances running on low-powered computers, VPSs, or single-board computers like a Raspberry Pi.

There is no limit on how many users it will support. Official documentation suggest it could handle 50, or more, users.

GoToSocial uses only about 250-350MB of RAM, and requires very little CPU power.