Earlier quoted context omitted.
How did they do it back in the day? Was basically everything from the tooling etc. just created inhouse from scratch?
The Dreamcast dev kits came with CodeWarrior as an IDE iirc.
https://jacobfilipp.com/MSJ/directx.html
"What happened to Windows CE on the SEGA Dreamcast?"
https://www.youtube.com/watch?v=QKHSlBi5qok
"Making Dreams Come True - Sega's Katana!"
https://www.youtube.com/watch?v=EIr9YnMgExA
Maybe it was for the Saturn and previous consoles?