Justice League and Justice League Unlimited are American animated series about a team of superheroes which ran from 2001 to 2006 on Cartoon Network. Since April 2006 it is being shown on Cartoon Network's sister channel, Boomerang and it is also shown on Teletoon every Friday night for Superfan Fridays. It is based on the Justice League and associated comic book characters published by DC Comics.
After the second season, the show was renamed Justice League Unlimited, had a vastly expanded cast of characters, and largely changed from two part episodes, to single episode stand-alone stories that often intertwined to form long (even season-long) story arcs.
Justice League and Justice League Unlimited were considered by their creators to be one series (albeit renamed), so Season "1" of Justice League unlimited is in fact Season "3" of the overall series, simply renamed, and with a new theme song and opening and closing credits. There were a total of 91 episodes, along with 2 crossover episodes of Static Shock in which the League appeared.
The show is, to date, the penultimate in a series of animated features that together constitute what is known as the DC animated universe (ending chronologically with Batman Beyond, although Justice League/JLU was the last series to air in real time). It consists of a series of 8 television shows and 4 films, largely surrounding DC Comics characters and their respective mythos.