MiniOS
MiniOS is a Debian-based Linux distribution which strives to be lightweight, modular, versatile and customisable. It comes in three editions, "Standard", "Toolbox" and "Ultra".
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ZimaOS
ZimaOS is an independently-developed, Linux-based operating system for personal servers and network-attached storage (NAS) devices. It features system-level support for remote access, RAID configuration, over-the-air (OTA) updates, and a browser-based user interface for managing the server.