All external AVR microcontrollers with the UPDI interface can be programmed and debugged with the on-board debugger with Atmel Studio.
External SAM microcontrollers that have a Curiosity Nano Board can be programmed and debugged with the on-board debugger with Atmel Studio.
PIC16F15244 Curiosity Nano can program and debug external PIC16F15244 microcontrollers with MPLAB X IDE.