Visitors to this metasite can find links to software, applications, examples, publications, theories, and histories of pseudospectra in investigation of non-normal matrices and operators. The Introduction page states, "Numerous tools have been suggested to describe non-normality and analyze its effects. These include classical tools of matrix and operator theory, such as the numerical range, the angles between invariant subspaces, and the condition numbers of eigenvalues. This web site is devoted to describing and illustrating pseudospectra, a further tool that has proved useful in a variety of circumstances." A list of publicly available software, with links, brief descriptions, and references is a highlight of the site. Most of the sections, including history, bibliography, and applications, are linked to MathSciNet and arXiv.org. The Examples page is particularly informative and contains formulae and color figures. Pseudospectra Gateway is a diverse, comprehensive resource for computational theorists.