The ArduPilot project supports many open source hardware designs. We don’t design the hardware ourselves (we are a software project), but we work closely with many organisations and companies that do make open source hardware. For those that don’t have their own VID we use a single VID/PID pair for all boards, then distinguish boards using the product ID strings in the bootloader and application firmware.
Schematics for some of the boards we support are here:
We use two PIDs, 5740 and 5741. We need two in order to support both single endpoint and dual-endpoint CDCACM devices on windows. Dual-endpoint devices need to have a different PID from single endpoint in order to install the correct driver.