Requires the free Source SDK Base 2007 from Steam. To install, extract all three files from BlackMesa.zip, then run BlackMesa-Setup.exe.
Prepare for an experience that you will find nostalgic, exciting and fresh. Black Mesa is a re-envisioning of Valve Software's seminal game Half-Life. You will re-visit the inaugural role of Gordon Freeman and his memorable journey through the Black Mesa Research Facility.