Waspmote is an open source wireless sensor platform specially focused on the implementation of low consumption modes which allows the sensor nodes ("motes") to be completely autonomous, that is battery powered. Lifetime of Waspmote sensor nodes may go from 1 to 5 years depending on the duty cycle and the radio used. Waspmote is based on a modular architecture. The idea is to integrate only the modules needed in each device optimizing costs. For this reason all the modules (radios, sensor boards, etc) plug in Waspmote through sockets. The  Waspmote WIFI module by Libelium is a certified Wi-Fi solution especially designed for customer who want to migrate their existing 802.15.4 architecture to a standard TCP/IP based platform without having to redesign their existing hardware. The Waspmote WIFI module incorporates 802.11 b/g radio, 32 bit processor, TCP/IP stack, real-time clock, crypto accelerator, power management unit and analog sensor interface. You will need batteries to use Waspmote as an autonomous device. Documentation: Waspmote Quick Tutorial Waspmote Site Waspmote Technical Guides Sensor Boards Technical Guides Networking Guides Developers Forum Videos Articles 50 Applications with Waspmote FAQ: Waspmote Vs. Arduino