If you don't have a license, consider moving to – it supports .xmcd files and is actively maintained.
PTC Mathcad 15 is a classic, but it's a legacy product. New downloads are only available to existing license holders via the official PTC Support Portal. ptc mathcad 15 download
PTC Mathcad 15 is a legendary engineering calculation software known for its unique whiteboard-like interface that combines live mathematical notation, text, and graphs. While PTC has moved on to Prime (the modern version), many engineers and academic institutions still rely on Mathcad 15 for legacy worksheet support, specific function libraries, or its classic interface. If you don't have a license, consider moving