DOSBOX
Used by 4 peopledosbox.com ↗

“For programming my demoscene productions, I usually design and prototype in DOSBox, then copy to the real metal for testing and refinement.”
Jim Leonard Interview, MobyGames co-founder, demoscene developer · via Uses This 
“I use DOSBOX to emulate X-COM.”
Kris Piotrowski Interview, Creative director and co-founder (CAPY) · via Uses This