The Intel MCS-51, commonly known as the "8051", is a single-chip microcontroller developed by Intel in 1980 for use in embedded systems. This "system on chip" houses 128 bytes of RAM, 4 KB of ROM, 2 timers, 1 serial port, and four ports on a single chip.[1] The increase in popularity and success of the 8051 led to the emergence of several versions of the microcontroller from other manufacturers (Intel allowed this). Its popularity remains today because it offers marketable availability, ease of use, energy efficiency, and integrated features such as USB and radio frequency. Not only is it important to look at the evolution of 8051, but also to take a look at the languages ​​that accompany it. But first let's start with the basics. What makes an 8051? Intel's MCS 51 is an 8-bit microcontroller and therefore its available operations are limited to 8 bits.[2] However, this does not limit the efficiency of the 8051. Among the specifications mentioned above, the typical CPU of an 8051 microcontroller introduced an integrated Boolean processor. This Boolean processor enables code size reduction through bit-level Boolean logic operations that are performed on selected internal registers and selected RAM locations. Therefore, greater efficiency can be found in programs that deal with the binary input and output conditions commonly found in digital control problems. The 8051's four registers further improve efficiency by reducing the time it takes to perform an interrupt. However, this is only the tip of the iceberg. Since its inception, the 8051 has undergone several changes to newer models, branching into many types or "device families" that contain its architecture. There are many microcontrollers that contain the architecture... half of the paper... .troller, the language used is totally dependent on the user and what they are trying to implement. If space is important to your application, perhaps the code should be written in assembly language. If you want something that can be used on many devices, then perhaps C is the way to go. Or, if one is Neo from the Matrix, machine code might be the only way to go to stop bad people from stealing and using your program. So what's in store for the future of the 8051? Many will argue that the 8051 has long since reached the highest stage of its evolution. And they're probably right. But unless the human species suddenly grows wings overnight or develops telepathy and stops using modern applications and technologies, it's a safe bet that the 8051 and its variants will be going strong for a while yet. Damn, they'll still be around when humanity colonizes space.