Fido is a versatile, open-source C++ library designed for machine learning applications, particularly in the fields of embedded electronics and robotics. This library features various implementations, including trainable neural networks, reinforcement learning techniques, and genetic algorithms, alongside a comprehensive robotic simulation environment. Additionally, Fido offers a human-trainable robot control system, as outlined by Truell and Gruenstein. Although the simulator is not included in the latest version, it remains accessible for users who wish to experiment with it on the simulator branch. With its modular design, Fido can be easily adapted for diverse projects in the robotics domain.