Delivery time: This product is not expected to be available again before 2024.
Possible alternative products can be found below.
The Teensy is a breadboard-friendly development board with loads of features in a, well, teensy package. The Teensy LC has a 32 bit ARM Cortex-M0+ microprocessor. You can program for the Teensy in your favorite program editor using C or you can install the Teensyduino add-on for the Arduino IDE and write Arduino sketches for Teensy.
More information is available on the website of Sparkfun and PJRC.