HackRF One from Great Scott Gadgets is a Software Defined Radio peripheral capable of transmission or reception of radio signals from 1 MHz to 6 GHz. Designed to enable test and development of modern and next generation radio technologies, HackRF One is an open source hardware platform that can be used as a USB peripheral or programmed for stand-alone operation.
Ubertooth One is an open source 2.4 GHz wireless development platform suitable for Bluetooth experimentation.
Open-Hardware Ultra-Low-Power Wireless Sensor Node
VirtualSense is an IEEE 802.15.4-compliant wireless sensor module running a Java-compatible 32 bit VM.