Haiku is a free and open-source operating system that was inspired by BeOS, a popular operating system from the late 1990s. Haiku is known for its ease of use, multimedia support, and ability to run on both PCs and Macs.
FreeBSD is a free and open-source Unix-like operating system. It is known for its stability, security, and networking features. FreeBSD is widely used in servers and embedded systems.
OpenBSD is another free and open-source Unix-like operating system. It is known for its focus on security and its commitment to developing innovative security features. OpenBSD is popular among security professionals and enthusiasts.
NetBSD is a free and open-source Unix-like operating system that is known for its portability. NetBSD can run on a wide variety of hardware architectures, from small embedded systems to large servers.
illumos is a free and open-source operating system that was derived from OpenSolaris, a discontinued operating system from Oracle. illumos is known for its performance, scalability, and compatibility with legacy Solaris applications.
These are just a few examples of the many operating systems that are available besides Windows, macOS, and Linux. Each operating system has its own unique strengths and weaknesses, and the best choice for a particular user will depend on their individual needs and preferences.