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) and Paul Reed completed a re-implementation of the original Oberon System for the Digilent Xilinx Spartan 3 FPGA Starter Board. The work included a revision of "Project Oberon", identified as Project Oberon (New Edition 2013). The system has since been ported to a Xilinx Spartan 6 FPGA Development Board by Saanlima Electronics. In 2015 Paul Reed collaborated with Victor Yurkovsky in the creation of OberonStation, a Xilinx Spartan 3-based computer designed specifically to run Oberon. A2, Yet another name for the Active Object System, 2003.<br> ALO, ARM Linux Oberon; in LNO family and for ARM CPU.<br> AOS, Active Object System,