In 1986, comic book distributor Scott Mitchell Rosenberg joined with Dave Olbrich and Tom Mason to form California-based Malibu comics. They were joined later by Chris Ulm. Initially, Malibu concentrated on licensed adaptations and black-and-white, creator-owned titles. More importantly, they were the publisher for Image Comics' first titles. Flush with Image cash and riding the early-90s comic boom, Malibu made the same decision in 1992 that several other small-and-mid-size publishers made around the same time: to start a superhero line. This imprint was eventually called the Ultraverse. While not as successful as, say, Valiant, the Ultraverse comics stood out from their competitors in many ways.

Aesthetically, they looked good. The print stock was of high quality and the coloring process was revolutionary. They were one of the first publishers to computer color (more about this later) and this resulted in a
distinctively vibrant appearance. Story-wise, they were a "traditional" superhero universe -- featuring both sci-fi and fantasy concepts. Like most of the universes launched around this time, they featured a tight internal continuity (in contrast to the Big Two's sprawling continuities) and were one of several of said publishers to operate with a "Bible," a story guide spelling out the major themes, events and characters of the Ultraverse's "history." As a publisher, they followed most of the trends of the time, printing variant issues and special issues to cash in on the speculator frenzy that marked the boom years. They also featured a relatively large amount of multi-title crossovers. This had the initial effect of supporting their lower-selling books, but later many fans reported collector's fatigue.

Their greatest accomplishment, from a fan's perspective, however, was the incredible talent they attracted. To begin with, the Ultraverse "Bible" was largely constructed around concepts developed by famed sci-fi writer Larry Niven. These were fleshed out in individual titles penned and penciled by such luminaries as Mike W. Barr, Steve Englehart, Steve Gerber, James D. Hudnall, Gerard Jones, James Robinson, Len Strazewski, Barry Windsor-Smith, Joe Maduriera, Mike Wieringo, Terry Dodson, and George Perez.

The beginning of the end for the Ultraverse came in 1994, with their purchase by Marvel comics. There have been several reasons given by various parties over the years for the acquisition but the primary one seems to have been rather simple -- Marvel wanted Malibu's coloring department. After shutting down the entire line, Marvel's limited relaunch met with limited success. Under Marvel's editorial control, quality had slipped. Industry veterans were replaced with unqualified young artists. There were too many forced "inter-Universe" crossovers. Add to that a bump in cover price and the burst of the speculator bubble, and you have the end of the Ultraverse. Marvel filed for bankruptcy in 1996. They published the last Ultraverse comic in January of 1997. During those few short years, though, the Ultraverse produced some of the best comics of the day by some of the best creators of the day.

Some reference links:

Wikipedia article on the Ultraverse.
http://en.wikipedia.org/wiki/Ultraverse

Sequart article on the Ultraverse.
http://www.sequart.com/articles/index.php?article=646