The electronic design automation (EDA) tool industry is big business, and commercial licenses are extremely expensive. Open standards have driven many proprietary EDA technologies to be publicly released as free/libre open source software (F/LOSS) and some have become IEEE standards. In this article, author Arthur Low reviews the history of key advances in ICs and EDA tools. The common theme presented in this article for the driver of technology innovation is the requirement to develop the most advanced microprocessor possible. Today, a low-cost, high-value-added business model can efficiently serve the market for IC subsystems licensed as intellectual property (silicon IP) in the form of compilable source code. Alternatively, for larger SoC designs, engineering budgets can be shifted from the purchase of a relatively small number of high-cost EDA tool licenses to open source EDA technologies that can be run on massive compute-server farms. The two business models are not theoretical, but realistic. The author explains how his company (Crack Semiconductor) developed commercially successful cryptographic silicon IP using entirely open source EDA technologies and how another company (SiCortex) pushed the limits of IC design and open source EDA tools by simulating and verifying a massively parallel supercomputer.