N'afọ 1977, Berkeley Software Distribution (BSD) bụ nke Computer Systems Research Group (CSRG) nke UC Berkeley mepụtara, dabere na mbipụta nke isii nke Unix site na AT&T. Ebe ọ bụ na BSD nwere koodu Unix nke AT&T nwere, AT&T gbara akwụkwọ (USL v. BSDi) na mbido 1990s megide Mahadum California. Nke a belatara mmepe na nnabata nke BSD.Na 1983, Richard Stallman malitere oru ngo GNU na ebumnuche nke ịmepụta sistemụ arụmọrụ UNIX n'efu. Dịka akụkụ nke ọrụ a, o dere GNU General Public License (GPL).
ịmepụta usoro sistemụ UNIX n'efu