Some direct download links for the Mathcad 15.0 Trial Edition have historically been hosted on PTC's servers.
, though you must have a valid PTC account and license to activate the software. PTC Community Installation and Requirements ptc mathcad 15 download
After the 30-day trial expires, the software automatically converts to "Mathcad Express," which is a free-for-life version with basic functionality like unit management and natural math notation. Some direct download links for the Mathcad 15