For ATARI users: How to create your own SpartaDOS X Cartridge + FujiNet Tools (using SIDE3 as an example.)
The following YouTube video shows how to create your own SpartaDOS X cartridge with the FujiNet tools, from scratch, using the SpartaDOS X Imager (SDXImager) tool.
For this video, I installed a fresh copy of Ubuntu Linux Desktop using default options, and added the following packages via a terminal:
sudo apt install build-essential git wine
Once everything is built, you can transfer it to the nearest FujiNet via WebDAV, by selecting Network in Files, and Connecting to the address of your FujiNet:
DAV://192.168.1.21/dav/
Links Used in the video
Ubuntu Linux: https://ubuntu.com/download/desktop
CC65 Compiler: https://github.com/cc65/cc65
MAD Assembler: https://github.com/tebe6502/Mad-Assembler
FujiNet Tools: https://github.com/FujiNetWIFI/fujinet-tools
FujiNet N: Handler: https://github.com/FujiNetWIFI/fujinet-nhandler
Altirra Emulator: https://www.virtualdub.org/altirra.html