This is a mega-repo for housing the http-client family of packages for Haskell. These packages provide a low level HTTP client engine (http-client), different backends for providing SSL support (http-client-tls and http-client-openssl), and higher-level APIs for user convenience (http-conduit).
If you're just getting started, it is recommended to use http-conduit, which is documented in the Yesod book.
Due to Haddock pulling the documentation directly from http-client, some "Since" notations give the version numbers of the http-client package. For reference, http-client-0.5.0 corresponds to http-conduit-2.2.0, and http-client-0.4.30 corresponds to http-conduit-2.1.11 .