There was. NT3.51 and NT4 were available for PowerPC (and MIPS) and was commercially sold, but only for IBM's workstations and the PowerPC ThinkPads, not for Power Macs. It was dropped by W2K.
And it's a single product - the NT3.51 and NT4 CDs you'd use to install an x86 PC also support PowerPC/MIPS/Alpha. Googling suggests you can run the MIPS version inside QEMU, but PowerPC is as much a bust as it was on PowerMacs.
