FreeBSD
FreeBSD is a UNIX-like operating system for the i386, amd64, IA-64, arm, MIPS, powerpc, ppc64, PC-98 and UltraSPARC platforms based on U.C. Berkeley's "4.4BSD-Lite" release, with some "4.4BSD-Lite2" enhancements.
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OmegaLinux
OmegaLinux is an Arch-based, rolling-release Linux distribution featuring the lightweight LXDE desktop. It is suitable for installation on older computers with as little as 1 GB of memory.