This talk tells the story of Mu, a native code editor written in Python (https://codewith.mu/). One Sunday afternoon I foolishly asked myself, ""How hard can it be to write a simple code editor?"" Several years later an international team of volunteers are still working on the project. We have had to address: Cross platform GUI development. Cross platform packaging solutions for Python. Creating an interactive visual debugger. Integrating with iPython notebook. Integrating with various IoT MicroPython devices. Integrating with frameworks such as PyGame/PyGameZero and Flask. Automating cross platform testing. Researching and testing UX with a challenging user base. Accessibility for all. Internationalisation. Creating an inclusive, welcoming and supportive community. This talk will explain why Mu was created, how Mu was created and, most importantly, shares the decision making, technical research and implementation details of Mu in the hope others can learn from our mistakes, mis-steps and muck-ups.