Technically UNIX being a trademark only the following systems are UNIX https://www.opengroup.org/openbrand/register/ https://www.opengroup.org/openbrand/regist

Technically UNIX being a trademark only the following systems are UNIX https://www.opengroup.org/openbrand/register/ https://www.opengroup.org/openbrand/register/ Many systems are definitely UNIX-like and many are to different degrees POSIX-compliant