https://www.romhacking.net/?page=utilities
From what I can tell, game development in general is very much Windows dominated at the moment too, though there is a slow move towards more OS independent tools and engines as time moves on.
- OpenMPT (music tracker)
- FamiTracker (music tracker for NES chiptunes)
- WinSCP (FTP,SFTP,etc client)
- WinMerge (file diff tool)