KiCad

KiCad is the leading open-source EDA suite for professional schematic capture and printed circuit board (PCB) layout.

KiCad is a free, cross-platform Electronic Design Automation (EDA) suite, providing an integrated toolset for the entire hardware design workflow. The software includes dedicated applications like Eeschema (schematic capture) and Pcbnew (PCB layout), plus a 3D viewer for mechanical checks. It supports complex designs, offering features like hierarchical schematics, integrated SPICE simulation, and up to 32 copper layers. KiCad runs on Linux, macOS, and Windows, making it a powerful, accessible alternative to commercial EDA packages for engineers and hobbyists worldwide.

https://www.kicad.org