The Digispark is an Attiny85 based microcontroller development board similar to the 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 for Compatible with Arduino IDE the Digispark is a great way to jump into electronics, or perfect for when for Compatible with Arduino is too big or too much.

Digispark Mini ATTINY85 Development Board

• The Digispark is shipped fully assembled except for the two included and easy to solder headers.
• Support for the Compatible with Arduino IDE 1.0+ (OSX/Win/Linux)
• Power via USB or External Source – 5v or 7-35v (12v or less recommended, automatic selection)
• 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)
• 
• Introduction:

  1.Support for Compatible with Arduino IDE 1.0+ (OSX / Win / Linux)

  2.Can be powered by USB or 5v or 7-35v (automatic matching) additional power supply

  3.500ma 5V regulator on motherboard

  4.USB Embedded (Serial Debug)

  5.6 I / O Pins (2 for USB support)

  6.8K flash (about 6K after bootload)

  7. USI of I2C and SPI)

  8.3 Pulse width modulation on the needle (more likely to use software pulse width modulation)>br>
  9.ADC on 4-pin

  10.Power LED indicator and Test / Status LED (in Pin0)

• 

• Digispark Mini ATTINY85 Development Board

•  Support for the IDE 1.0+ (OSX / Win / Linux)

  · Power via USB or External Source-5v or 7-35v (automatic selection)

  · On-board 500ma 5V Regulator

  · Built-in USB (and serial debugging)

  6 I / O Pins (2 are use 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)

  · I2C and SPI (vis USI)

  · PWM on 3 pins (more possible with Software PWM)

  · ADC on 4 pins

  · Power LED and Test / Status LED (on Pin0)M

• en.wikipedia.org