MathSoft, Inc.:Developers of Mathcad, the leading technical calculation software for engineers, scientists, researchers and analysts, plus other leading technical software for industry and education.
Adventures in Mathcad: Mathcad worksheets related to the teaching of chemistry. From Kevin Lehmann of Princeton University.
BarBuilder: A plugin for MathCAD that renders transparent 3D bars.
Introduction to Mathcad: Teaches basic Mathcad skills, including graphing, solving, and annotation. Designed for students and for Mathcad 6 and above.
Mathcad at Adept Scientific: Links to free downloads, application files, education files, technical support files, and updates to Mathcad.
Mathcad Collaboratory: Official online forum for Mathcad users. Provides a means to share tips and worksheets for using Mathcad in many engineering and scientific disciplines.
MathCAD File Site: Collection of math, physics, and engineering-related Mathcad worksheets. From the Pennsylvania State University.
Mathcad Files Around the World: Large collection of links to Mathcad files on the Web. Most files listed are available for free download; some are offered for sale by their creators.
Mathcad Mailing List Archives: Archives of the Mathcad email list, a worldwide discussion group, with gripes, suggestions, and lots of tips and solutions from Mathcad users.
MathParser: A utility that parses Mathcad's MathML output into LaTeX.
SCIA Scientific Software: Official Mathcad distributor for Belgium and Luxembourg. Products and services.