Proteus is software by Labcenter Electronics that provides a full workflow environment for designing schematics, simulation (including code on microcontrollers) along with PCB design. Simulation brings to the table the ability to save plenty of time fault finding and/or testing a concept.
PCB development from a proven simulated circuit helps to ensure no surprises with the final product.
Proteus is popular for both academic use and professional (commercial) use. Buying your license from Core Electronics brings with it our support for your projects.