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 IA-32, x86-64, ARMv7, and ARMv8/64, formerly runs on 68k, PowerPC(5xx-G5), MIPS, ARMv4T, ARMv5, and ARMv6.

Native User Interface
UserBoard 1.0