The Digispark compatible developing board is an Attiny85 based microcontroller, board similar to the Arduino line, only cheaper, smaller, and a bit less powerful. With a whole host of shields to extend its functionality and the ability to use the familiar Arduino. IDE the Digispark is a great way to jump into electronics, or perfect for when an Ard. boards is too big or too much.
Features
6 I/O Pins (2 are used for USB only if your program actively communicates over USB otherwise you can use all 6 even if you are programming via USB)
8k Flash Memory (about 6K after bootloader)
ADC on 4 pins
Built-in USB(and serial debugging)
I2C and SPI(vis USI)
On-board 500ma 5V Regulator
Power LED and Test/ Status LED (on Pin0)
Power via USB or External Source or 7-16 v to 5 v (automatic selection).
PWM on 3 pins (more possible with Software PWM)
Support for the Arduino IDE 1.0+ (OSX / Win / Linux)
