Not since 2002. Irix, HP/UX, Solaris. Correction: It has been pointed out to me that I'm currently using macOS which, Darwin non-withstanding, is technically a

Not since 2002. Irix, HP/UX, Solaris. Correction: It has been pointed out to me that I'm currently using macOS which, Darwin non-withstanding, is technically a proprietary UNIX.