In one of the lowest spec examples of the last one, [gvl610] has got an up-to-date Linux kernel to boot on a vanilla Arduino Uno.

Arduino has announced the new UNO R4 board family for prototyping and learning. The new models feature a faster microcontroller, a USB-C connector, improved power, Wi-Fi and Bluetooth LE, and more.

Arduino has launched its next generation of UNO boards, introducing a 32-bit Renesas microcontroller and Espressif ESP32-S3 module, one-click cloud connectivity and plenty of I/O plus a 12×8 red LED ...

Arduino collaborated closely with partners Renesas and Espressif to create the ‘most compatible and powerful maker board on the market’.