This is an open-source Feather-format board that you can build yourself. It’s based on the Espressif ESP32-P4 high performance RISC-V processor, and it runs uLisp:
The ESP32-P4 is a dual-core RISC-V processor running at up to 400MHz, with 768KB of on-chip SRAM, 32Mbytes of on-chip PSRAM, and up to 32Mbytes of external flash. The board can be powered through the USB port, or from a LiPo battery with charging through the USB port.
It’s fast, and runs the Tak benchmark in about 1.5 seconds.
For full details see ESP32-P4 Feather Board on Technoblogy.