What makes this different from ESP8266?

As we know, ESP8266 is a very famous wireless platform. Can someone give me a comparison between ESP8266 and W600?

The ESP8266 has a Tensilica processsor. This board has an ARM processor.

So will it be possible to write software in C with FreeRTOS and compiled with GCC? That would be great, a major benefit over the ESP8266.

Yes. And we will have a:FreeRTOS, so it will easily integrate with some AWS services.