A UNIX-LIKE<\/a> system is an OPERATING-SYSTEM<\/a> that behaves in a manner similar to the original UNIX<\/a> developed at BELL-LABS<\/a>. These systems are characterized by their multi-user and multi-tasking capabilities, often adhering to the POSIX<\/a> standards to ensure software compatibility across different platforms. The design philosophy emphasizes small, modular tools that can be combined via PIPES<\/a> to perform complex tasks.<\/p> Major branches of the UNIX-LIKE<\/a> family include LINUX<\/a>, which utilizes the LINUX-KERNEL<\/a> created by LINUS-TORVALDS<\/a>, and the BSD<\/a> family, which originated at the UNIVERSITY-OF-CALIFORNIA-BERKELEY<\/a>. While MACOS<\/a> by APPLE<\/a> is fully certified as UNIX<\/a>, it is frequently grouped with UNIX-LIKE<\/a> systems due to its DARWIN<\/a> base and OPEN-SOURCE<\/a> components.<\/p> For technical specifications, see The POSIX Standard<\/a> and the Linux Kernel Archives<\/a>.<\/p>