http://espressif.com/en/products/esp8266/
ESP8266
ESP8266 is a highly integrated chip designed for the needs of a new connected world. It offers a complete and self-contained WiFi networking solution, allowing it to either host the application or to offload all WiFi networking functions from another application processor.
ESP8266 has powerful on-board processing and storage capabilities that allow it to be integrated with the sensors and other application specific devices through its GPIOs with minimal development up-front and minimal loading during runtime. Its high degree of on-chip integration allows for minimal external circuitry, and the entire solution, including front-end module, is designed to occupy minimal PCB area.
Features
SDIO 2.0, SPI, UART
32-pin QFN package
Integrated RF switch, balun, 24dBm PA, DCXO, and PMU
Integrated RISC processor, on-chip memory and external memory interfaces
Integrated MAC/baseband processors
Quality of Service management
I2S interface for high fidelity audio applications
On-chip low-dropout linear regulators for all internal supplies
Proprietary spurious-free clock generation architecture
Integrated WEP, TKIP, AES, and WAPI engines
https://nurdspace.nl/ESP8266https://nurdspace.nl/images/e/e0/ESP8266_Specifications_English.pdfThese are the ones I am playing with
https://www.adafruit.com/product/2471