zdoom-BLANKLEY.zip contains an easy to run copy of the freedoom content pack and the zdoom engine for Windows.
Source for both are available at http://freedoom.github.io and http://www.zdoom.org, respectively. Specfic versions: zdoom-2.8pre-1952-g824801a.7z freedoom-0.10.1.zip
Download, extract, and drag and drop BLANKLEY.wad onto zdoom.exe to play. The WAD replaces E1M1, or the very first level.
BLANKLEY.wad is the standalone PWAD, for those on alternate platforms.