Hi @matccc.
The board's schematic and PCB design files have been released under the CC BY-SA 4.0 license. They are available for download from the links on the board's documentation page:
https://docs.arduino.cc/hardware/uno-q/
The open source Debian Linux operating system is used on the board's microprocessor.
The Arduino sketches that run on the board's STM32U585 microcontroller are built on the ["Arduino Zephyr Boards" platform, which is offered under the Apache 2.0 open source license:
The platform's core is based on the open source Zephyr OS:
Arduino IDE, which may be used to develop sketches for the board is offered under the AGPL 3.0 open source license.
Arduino CLI, which may be used to develop sketches for the board is offered under the GPL 3.0 open source license.
The new Arduino App Lab development tool that is used to create projects for the UNO Q board is offered under the GPL 3.0 open source license (the source code is available for download from the link here, and the GitHub repositories will be made public soon).
Quite a few different pieces of software are used with the UNO Q in the common use case, and of course the user has the freedom to use many others. So it is difficult to provide a comprehensive answer to such a question. If you have any doubts about the licensing of any other aspects, just let us know and we'll try to clarify.
It is available for download from the link on this page:
Keep in mind that the Raspberry Pi boards are not open source hardware.
You also won't find datasheets for the Broadcom microprocessors used by the RPi SBCs (though the situation is better for the Raspberry Pi RP2040 and RP2350 microcontrollers).