The crowdfunded Open-V implementation of RISC V comes to mind. https://www.crowdsupply.com/onchip/open-v https://www.crowdsupply.com/onchip/open-v However, it

The crowdfunded Open-V implementation of RISC V comes to mind. https://www.crowdsupply.com/onchip/open-v https://www.crowdsupply.com/onchip/open-v However, it doesn't look like they're going to come remotely close to hitting their funding goal. Fabricating chips is expensive.