as The Simpsons (since 1989) as part of a "renaissance" of American animation. While US animated series also spawned successes internationally, many other countries produced their own child-oriented programming, relatively often preferring stop motion and puppetry over cel animation. Japanese anime TV series became very successful internationally since the 1960s, and European producers looking for affordable cel animators relatively often started co-productions with Japanese studios, resulting in hit series such as Barbapapa (The Netherlands/Japan/France 1973–1977), Wickie und die starken Männer/小さなバイキング ビッケ (Vicky the Viking) (Austria/Germany/Japan 1974), and The Jungle Book (Italy/Japan 1989). Switch from cels to computers Computer animation was gradually developed since the 1940s. 3D wireframe animation started popping up in the mainstream in the 1970s, with an early (short) appearance in the sci-fi thriller Futureworld (1976). The Rescuers Down Under was the first feature film to be completely created digitally without a camera. It was produced in a style that's very similar to traditional cel animation on the Computer Animation Production System (CAPS), developed by The Walt Disney Company in collaboration with Pixar in the late 1980s. The so-called 3D style, more often associated with computer animation, became the dominant technique following the release of Pixar's Toy Story (1995), the first computer-animated feature in this style. Most of the cel animation studios switched to producing mostly computer animated films around the 1990s, as it proved cheaper and more profitable. Not only the very popular 3D animation style was generated with computers, but also most of the films and series with a more traditional hand-crafted appearance, in which the charming characteristics of cel animation could be emulated with software, while new digital tools helped developing new styles and effects. Economic status In 2010, the animation market was estimated to be worth circa US$80 billion. By 2020, the value had increased to an estimated US$270 billion. Animated feature-length films returned the highest gross margins (around 52%) of all film genres between 2004 and 2013. Animation as an art and industry continues to thrive as of the early 2020s. Education, propaganda and commercials The clarity of animation makes it a powerful tool for instruction, while its total malleability also allows exaggeration that can be employed to convey strong emotions and to thwart reality. It has therefore been widely used for other purposes than mere entertainment. During World War II, animation was widely exploited for propaganda. Many American studios, including Warner Bros.