Y-OS

Y-System (formerly known as Y-OS until September 24, 2014) is a family operating system. The first released was Y-OS 1.0, released February 1997. The current version runs only on x86-64 and ARMv8/64, it was formerly runs on i386, i486, i586, 68k, PowerPC(5xx-G5), MIPS, Alpha, ARMv4T, ARMv5, ARMv6 and ARM v7.

Native User Interface
UserBoard 1.0