PCem
https://pcem-emulator.co.uk
This should be included in the repository since it offers a means to emulate older x86 PCs for running older software easily, with emulated hardware.
Is it Open Source? Yes
How many users do you anticipate will use this software? Several
Link to tarball: https://pcem-emulator.co.uk/files/PCemV13.1Linux.tar.gz