| Produttore | Tipo di produzione |
| AMD | Enhanced 8051 parts (no longer producing 80x51 parts) |
| Amtel | FLASH and semi-custom parts |
| Dallas | Battery backed, program download, and fastest variants |
| Intel | 8051 through 80c51gb / 80c51sl |
| Matra | 80c154, low voltage static variants |
| OKI | 80c154, mask parts |
| Philips | 87c748 thru 89c588 - more variants than anyone else |
| Siemens | 80c501 through 80c517a, and SIECO cores |
| SSI | 80x52, 2 x HDLC variant for MODEM use |