Roswell is an American science fiction television series developed, produced, and co-written by Jason Katims.The series debuted on October 6, 1999 on The WBand moved to UPN for the third season. The last episode aired May 14, 2002. In the United Kingdom, the TV series aired as both Roswell High and Roswell. The series pilot is based on the Roswell High young adult book series, written by Melinda Metz and edited by Laura J. Burns, who became staff writers for the television series.
The series premiered on October 6, 1999 on The WB Television Network in the United States to generally favorable reviews. Although it quickly garnered an outspokenfanbase, the series almost immediately entered a steady ratings decline that kept the show under constant threat of cancellation.
In response to the problems the series had with ratings during its first season, The WB ordered the relationship-driven standalone episodes of the early first season to be replaced with more science fiction themes and multi-episode plot arcs. Starting with the second season, veteran science fiction writer Ronald D. Moore was brought in to join Katims as an executive producer and showrunner and to further develop the science fiction elements of the show.
Not all fans responded favorably to the shift to more science fiction-driven storylines during the second season and the ratings continued to disappoint WB, causing the network to finally cancel the show on May 15, 2001, after the show's second season finale, a move widely anticipated due to the sagging ratings. 20th Century Fox (the studio that produced the show) was able to persuade UPN to pick it up for a third season as a package deal when UPN outbid The WB for one of its popular flagship series, Buffy the Vampire Slayer.
During the 2001 - 2002 television season, Roswell, in its third season, aired directly after Buffy on Tuesday nights on UPN, though it was unable to hold on to the audience Buffy provided as a lead-in. This eventually resulted in the show's cancellation from UPN as well. Roswell aired its final episode on May 14, 2002.