Dexter as he appears in his hanna barbera logo in 1997
Hanna-Barbera Cartoons was the original parent company for Cartoon Network Studios, the company that produced Dexter's Laboratory. H-B was founded in 1957 by former MGM animators William Hanna and Joseph Barbera (both of which created the famed cat-and-mouse duo Tom and Jerry at MGM in 1940), when MGM shut down their original animation unit. Hanna-Barbera helped develop the standard limited animation techniques that were to be utilized for television animation. H-B's first TV series was the Ruff and Reddy show that year, and had their first big success in 1958 with The Huckleberry Hound Show. Over the years, Hanna-Barbera continued making various animated TV shows and introduced many popular cartoon characters of the time including The Flintstones, Yogi Bear, The Jetsons, Magilla Gorilla, Wacky Races, Scooby-Doo, and many others.
In 1991, Turner Broadcasting bought the Hanna-Barbera library, and in 1994, with the growing popularity of Turner's then-new cable channel Cartoon Network, Hanna-Barbera founded a division named Cartoon Network Studios, which was designed to produce new animation exclusively for Cartoon Network under the H-B brand name or Cartoon Network's name. With the premiere of World Premiere Toons in 1995, young H-B animator Genndy Tartakofsky created a pilot for "Dexter's Laboratory" to air on the show (later aired as a regular episode in the main series, retitled "Changes"), and the following year, Dexter was greenlit to become Cartoon Network's first "Cartoon Cartoon" animated series.
Initially, the ending of the show contained a logo for Cartoon Network Studios with a byline reading "A Division of Hanna-Barbera Cartoons," but for the 1997-1998 season, the show was released under Cartoon Network Studio's parent company's name (by this point, Turner had merged with Time Warner), initially with the above-pictured logo at the end, and on the Ego Trip TV movie with the classic 1980s H-B "Swirling Star" closing logo (which was also used on The Powerpuff Girls at the time).
In 1998, Hanna-Barbera became an in-name-only unit, now owned by Warner Bros. Animation, and Cartoon Network Studios became a separate facility, dropping using Hanna-Barbera's name in 2001 with the death of William Hanna (all subsequent episodes since then carry a Cartoon Network Studios logo and copyright.)