PICAXE is the name of a UK-sourced microcontroller

Microcontroller

A microcontroller is a small computer on a single integrated circuit containing a processor core, memory, and programmable input/output peripherals. Program memory in the form of NOR flash or OTP ROM is also often included on chip, as well as a typically small amount of RAM...

 system based on a range of Microchip

Microchip Technology

Microchip Technology is an American manufacturer of microcontroller, memory and analog semiconductors. Its products include microcontrollers , Serial EEPROM devices, Serial SRAM devices, KEELOQ devices, radio frequency devices, thermal, power and battery management analog devices, as well as...

 PICs

PIC microcontroller

PIC is a family of Harvard architecture microcontrollers made by Microchip Technology, derived from the PIC1650 originally developed by General Instrument's Microelectronics Division...

. There are 13 PICAXE variants of differing pin counts from 8 to 40 pins. Initially marketed for use in education and by electronics hobbyists, they are also used in commercial and technical fields, including rapid prototype development. All use pre-loaded factory bootstrap

Booting

In computing, booting is a process that begins when a user turns on a computer system and prepares the computer to perform its normal operations. On modern computers, this typically involves loading and starting an operating system. The boot sequence is the initial set of operations that the...

 interpretation code to allow user generated programs

Computer program

A computer program is a sequence of instructions written to perform a specified task with a computer. A computer requires programs to function, typically executing the program's instructions in a central processor. The program has an executable form that the computer can use directly to execute...

 to be downloaded using a simple USB or RS-232

RS-232

In telecommunications, RS-232 is the traditional name for a series of standards for serial binary single-ended data and control signals connecting between a DTE and a DCE . It is commonly used in computer serial ports...

 serial connection

Serial port

In computing, a serial port is a serial communication physical interface through which information transfers in or out one bit at a time...

.

Based upon a variety of Microchip PICs, the chips come in a number of DIP footprints, from an 8-pin, 128-byte program capacity device through to 28 pin and 40-pin, 16k-byte (as 4 x 4kB slot) program capacity devices.