FreeBSD is a free and open-source Unix-like operating system descended from the Berkeley Software Distribution (BSD).
It has similarities with Linux, with two major differences in scope and licensing. FreeBSD maintains a complete system (i.e. the project delivers a kernel, device drivers, userland utilities, and documentation), as opposed to Linux only delivering a kernel and drivers, and relying on third-parties for system software. Its source code is generally released under a permissive BSD license, as opposed to the copyleft GPL used by Linux.
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