GNU/Linux naming controversy lacking. The GNU kernel was called GNU Hurd. The Hurd followed an ambitious design which proved unexpectedly difficult to implement and has only been marginally usable. Independently, in 1991, Linus Torvalds released the first version of the Linux kernel. Early Linux developers ported GNU code, including the GNU C Compiler, to the kernel. The free software community adopted the use of the Linux kernel as the missing kernel for the GNU operating system. This work filled the remaining gaps in providing a completely free operating system. Over the next few years, several suggestions arose for naming operating systems using the
V (operating system) modular windowing system for both local and remote applications. The little-known W Window System got its name because it was first hosted on the V operating system, and the better-known X Window System in turn got its name because its first version was based partly on W. V also spawned another pure microkernel effort at Apple Computer known as Vanguard, which added a number of improvements to the basic system. Vanguard later disappeared in a reorganization. The Tektronix VM700 television measurement instrument was developed in a networked V environment in the late 1980s and ran a lightly modified version of