There are many links on this page that point to a page on CTAN, or the Comprehensive TeX Archive Network. CTAN is a single source for packages and tools designed for TeX. If you’ve found a package on CTAN, it’s very likely that it’s already available on your computer. If not, find your ‘distribution’ (TeX Live, MacTeX, MiKTeX, …) on this page for helpful links on how to install the package automatically.

CTAN also provides introductions and links to documentation for its entries. The pages listed here will almost always have both – just look in the large gray box in the middle of the page.