...Unlike Steam it DOES NOT download 90MB of 'updates' to complete itself after a ~1.50MB download.
The whole tool is currently just 474 KB once extracted.
Download: http://sourceforge.net/projects/dooms-19-winx64/files/latest/download
Source Code available at: http://sourceforge.net/projects/dooms-19-winx64/files/source/
Report Bugs, Issues, Annoyances, Exceptions, etc. at: http://sourceforge.net/p/dooms-19-winx64/discussion/bugs/
Separate Forum for Improvements at: http://sourceforge.net/p/dooms-19-winx64/discussion/improvements/
This is just episode one (Shareware), unless you have legit DOOM and copy the IWAD into the PrBoom folder. ...