DOSEMU is a discontinued DOS emulator / virtualizer which allwed you to run MS-DOS software naively on your CPU. This had obvious speed advantages over the updated and current alternative DOSBox. DOSBox emulates an entire computer common to the area when MS-DOS was popular while DOSEMU would run software directly on the CPU. This performance-difference mattered around the turn of the century. Today it's a non-issue.
|DOSEMU has not been updated since 2007. It is still possible to download and try to use it but there is little point and DOSBox really is a better, updated and more versatile alternative for running DOS software.
You can get the latest version of DOSEMU which is 1.4 from http://www.dosemu.org/stable/ if you are really curious. Be aware that you will have a hard time getting this 2007-era software running on a modern distribution in 2019. Your millage will vary.