MicroPython is a lean and efficient Python implementation for microcontrollers, embedded, and mobile systems (which also runs just as fine on desktops, servers, and clouds).
There're following major changes since 1.5:
1. LwIP module support for embedded TCP/IP networking. 2. IPv6 support in the Unix port. 3. Beta support for persistent bytecode (similar to CPython's .pyc) 4. 64-bit NaN boxing (improved floating-point performance if enabled). 5. Support for new official PyBoards PYBv1.1 and PYBLITEv1.0. 6. Long int constant folding during bytecode compilation (glad that CPython will catch up in that area thanks to FAT Python project). 7. There's a ongoing crowdfunding campaign to fund complete and well-maintained MicroPython port to ubiquitous ESP8266 WiFi SoC, and improve networking and IoT support in MicroPython in general: