Arduino Yún

http://www.arduino.cc/en/Main/ArduinoBoardYun?from=Main.ArduinoYUN

Because the Yún has two processors, the summary section shows the characteristics of each one in two separate tables.

AVR Arduino microcontroller
Microcontroller	ATmega32u4
Operating Voltage	5V
Input Voltage	5V
Digital I/O Pins	20
PWM Channels	7
Analog Input Channels	12
DC Current per I/O Pin	40 mA
DC Current for 3.3V Pin	50 mA
Flash Memory	32 KB (of which 4 KB used by bootloader)
SRAM	2.5 KB
EEPROM	1 KB
Clock Speed	16 MHz
Linux microprocessor
Processor	Atheros AR9331
Architecture	MIPS @400MHz
Operating Voltage	3.3V
Ethernet	IEEE 802.3 10/100Mbit/s
WiFi	IEEE 802.11b/g/n
USB Type-A	2.0 Host
Card Reader	Micro-SD only
RAM	64 MB DDR2
Flash Memory	16 MB
PoE compatible 802.3af card support (see the note below)
Length	73 mm
Width	53 mm
Weight	32 g