There are websites archiving and sharing LaTeX tools and packages and providing catalogs for easy look-up.
This network consists of many servers world-wide, which store the biggest collection of TeX-related material. Nearly every serious LaTeX package can be found in this archive. On the homepage, you will find search features or you may just start browsing the archive directories.
This catalog offers a topical, a hierarchical, a brief, and an alphabetical index to nearly 4,000 TeX and LaTeX packages and tools. It is closely related to CTAN, which actually stores the software. This site is great for browsing especially if you work on a topic, but don't know which packages may exist for that purpose.
Nearly all fonts available for use with LaTeX are listed here. About a dozen categories, such as...