The talk given at the FOSDEM conference in 2023 was about MicroPython. The speaker explained the concept of microcontrollers and how they differ from microprocessors. He discussed the differences between interpreters and compilers and how Python is typically run. He then introduced MicroPython, which allows Python code to be run on microcontrollers. He demonstrated various examples, such as blinking LEDs and controlling displays, using different microcontroller devices. The speaker also discussed limitations and considerations when using MicroPython, such as RAM usage and compiling libraries. Overall, the talk provided an introduction to MicroPython and its applications in the world of free and open source software development.