The M8051 is a configurable soft-core implementation of the industry standard 8051 microcontroller that features a clock compatible twelve clocks per machine cycle architecture. This microcode-free ...

IP-AL8051S soft core is instruction set compatible with the 8051 8-bit microcontroller architecture and can achieve average performance of up to 20 million instructions per second.

Some other old silicon survives in the form of cores incorporated into other chips, for example the venerable Intel 8051 ... The architecture survives in some of NXPs microcontroller ranges.