Umbriel (moon) that obliterated its older surface. Covered by numerous impact craters reaching in diameter, Umbriel is the second most heavily cratered satellite of Uranus after Oberon. The most prominent surface feature is a ring of bright material on the floor of Wunda crater. This moon, like all moons of Uranus, probably formed from an accretion disk that surrounded the planet just after its formation. The Uranian system has been studied up close only once, by the spacecraft "Voyager 2" in January 1986. It took several images of Umbriel, which allowed mapping of about 40% of the moon’s surface. Umbriel, along with
Oberon (operating system) Linux Revival. A version of NO which uses Linux as a HAL and runs on x86, ARM, and MIPS.<br> OP2, The Portable Oberon-2 Compiler. OP2 was developed to port Oberon onto commercially available platforms.<br> PACO, (scope) PArallel COmpiler. Appears in A2. Compiles each scope in an independent thread. <br> RISC5, the CPU of Project Oberon 2013 based upon Wirth's RISC architecture. Not to be confused with RISC-V.<br> UnixAOS, Unix-based AOS.<br> WinAOS, Windows-based AOS.<br> Oberon (operating system) The Oberon System is a modular, single-user, single-process, multitasking operating system written in the programming language of the same name. It was originally developed