A microcontroller developed by Intel in 1980 for use in embedded products and still (1999) one of the most popular microcontrollers.
The 8051/8031 cores are used in over 100 devices from 10 independent manufacturers such as Dallas and Philips.
[What is the difference between the 8031/8051/8052?]
See also CAS 8051 Assembler, as31 assembler, 51forth.
The 8031/51 series microcontroller.
Intel MCS51 series microcontrollers.