Operating system kernel originated in 1991, as a project of Linus Torvalds, while a university student in Finland. He posted information about his project on a newsgroup for computer students and programmers, and received support and assistance from volunteers who succeeded in creating a complete and functional kernel. Linux is Unix-like, but was developed without any Unix code, unlike BSD and its variants. Because of its open license model, the Linux kernel code is available for study and modification, which resulted in its use on a wide range of computing machinery from supercomputers to smart-watches. Although estimates suggest that Linux is used
GEOS (8-bit operating system) fully reverse-engineered and rewritten as C for the cc65 compiler suite. The reverse-engineered source code has been made available at Github. Dozens of official and third-party applications and other products were produced for GEOS. Among the most important and popular were the following: GEOS (8-bit operating system) GEOS ("Graphic Environment Operating System") is a discontinued operating system from Berkeley Softworks (later GeoWorks). Originally designed for the Commodore 64 and released in 1986, it provides a graphical user interface for this popular 8-bit computer. GEOS closely resembles early versions of the classic Mac OS and includes a graphical word processor (geoWrite)