While the newer Raspberry Pi A+, B+ and B2 boards feature the new 40-pin connector, the Raspberry Pi boards Model A and B have a 26-pin expansion header, but both are use to access GPIOs, UART, SPI, I2C and interface with external hardware, and many add-ons boards have been developed for the Raspberry Pi. But what if you’d like to use R-Pi add-ons board on your PC, or instead you are developing your own add-on board, but would like to do so directly on your PC for convenience? DonglePi is the answer.
It’s a small USB dongle with Atmel SAMD21 MCU and a 26-pin Raspberry Pi compatible header, that you could use connect to your Android/Linux/Windows PC to play with GPIO, I2C, SPI, Serial, PWM just like on a Raspberry Pi, and using RPi/GPIO or smbus Python libraries for programming.
The project is still in development, and so far most interfaces are working except PWM which needs to be worked on. The whole software and hardware (Eagle Schematics & PCB) are released under a Creative Commons CC BY-NC 4.0 license.
The hardware can not be purchased (yet), but you could also make a prototype with a breadboard, an Atmel SAMD21 development board, and Pi Cobler kit just like the developer (gbin) started with as shown below.
All connections, hardware and software are documented on github.
Thanks to Zoobab for the tip.

Jean-Luc started CNX Software in 2010 as a part-time endeavor, before quitting his job as a software engineering manager, and starting to write daily news, and reviews full time later in 2011.
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