There are many circuit design softwares available to satisfy diversified layout requirement, including free PCB design software, online free PCB design softwares, and industrial PCB softwares. This is the PCB design software list and brief introduction. You can have a comparison based on the introduction. 1.PROTEL (Altium Designer) PORTEL company introduced the circuit design software (CAD) PROTEL in the circuit industry in the the late 80s, 20th century, which is deservedly ranked highly among many EDA software and is circuit designers’ preferred software. Many universities’ circuit specialties have the specific courses to learn how to use PROTEL, and almost all of the circuit companies have used it for their work. It is good for one or two layers’ board, however, it becomes a little bit hard to use when it comes to more than 4 layers, not to mention the PCB design in signal transmission of high frequency and high-speed digitization. PADS (PowerPCB) You can describe it the king of CAD in the low side.