Espressif ESP32 is one of the most awaited chip for IoT applications as it combines a dual core processor, WiFi, Bluetooth 4.0, and various I/Os. The good news is that you can now purchase ESP32 for 19 RMB ($2.85) on Taobao, or if you are not based in China, contact Espressif by email at sales [at] espressif.com.
You can also find documentation, hardware and software resources on a Espressif ESP32 page , including a getting started guide, ESP32 SDK, ESP32 reference manual, ESP-WROOM-32 datasheet, and more.
If you are unsure whether your project would benefit from ESP32 over the cheaper ESP8266, I found an interesting table in Espressif Introduction document, showing how the processors are used in different applications.
Jean-Luc started CNX Software in 2010 as a part-time endeavor, before quitting his job as a software engineering manager, and starting to write daily news, and reviews full time later in 2011.