Linux the fledgling operating system; code licensed under the GNU GPL can be reused in other computer programs as long as they also are released under the same or a compatible license. Torvalds initiated a switch from his original license, which prohibited commercial redistribution, to the GNU GPL. Developers worked to integrate GNU components with the Linux kernel, making a fully functional and free operating system. Linus Torvalds had wanted to call his invention "Freax", a portmanteau of "free", "freak", and "x" (as an allusion to Unix). During the start of his work on the system, some of the project's makefiles
EPOC (operating system) system to drive their next generation of devices. First, however, they needed to engineer a 16-bit single-board computer—something that was extremely difficult at the time. They codenamed the project "SIBO", for "single-board organiser" or "sixteen-bit organiser". To develop the SIBO hardware and software, they needed samples of the 16-bit microprocessors they would be programming; but it took more than a year to secure the chips, which caused a significant delay. By 1987, development of EPOC was underway: It was a single-user, preemptive multitasking operating system designed to run in read-only memory (ROM). The operating system and its programmes were written