Tor Browser:
Tor Browser contains everything you need to safely browse the Internet.

Orbot:
Tor for Google Android devices.

Tails:
Live CD/USB operating system preconfigured to use Tor safely.

Nyx:
Terminal (command line) application for monitoring and configuring Tor.

Relay Search:
Site providing an overview of the Tor network.

Pluggable Transports:
Pluggable transports help you circumvent censorship.

Stem:
Library for writing scripts and applications that interact with Tor.

OONI:
Global observatory monitoring for network censorship.