Tartakovsky has acknowledged taking some of his inspiration from the Frank Miller graphic novel Ronin, including the premise of a master-less samurai warrior thrown into a dystopic future ahead of our present.
Many characters Samurai Jack encounters in the dark future reference cartoon characters, mainly from Hanna/Barbara cartoons who's characters are owned by Cartoon Network and also from various Japanese anime.
When Samurai Jack came back for its 5th season, it got a lot of support from fans as the show shifted from airing on the usual Cartoon Network to Adult Swim. This interesting shift meant that the writers had a more creative way to advance the plot without the restrictions placed by Cartoon Network, whose target audience is children and young adults.
In Seasons 1-4, Aku was voiced by Mako, who passed away in 2006. For Season 5, he was replaced by Greg Baldwin. Greg Baldwin also replaced Mako as the voice of Uncle Iroh in Avatar: The Last Airbender, as Mako passed away during Season 2 of that show.
Throughout the series, certain subtle features can be seen in Genndy Tartakovsky's other famous animation, Dexter's Lab. In both, the animation style of the protagonists were kept simple, yet obviously more sharp-angled than other characters to make him stand out. Also, certain sounds are seen in both, such as the clinking sound when the sun hits an object (e.g. Jacks katana and Dexter's robot).
The trivia items below may give away important plot points.
As the last episode of this series aired there were many cameos throughout the episode. Including the Giant Samurai, the frogs, rave party people, cave man who taught Jack how to jump good, arrow warriors, and of course the Scotsman children and himself.