The GNU project was started by Richard Stallman in 1983. His aim was to create a computer system fully free to modify, share and publish modified work. He and a group of developers started with creating copies, of each piece of Unix software, which are free to modify and share. The remaining part of GNU was the kernel, called the GNU Hurd, which is not yet completely built. The more popular Linux kernel is used instead. Linux vs. Unix or BIOS