Hard to believe that it's been almost a decade since the weekly adventures of FBI Agents Mulder and Scully left TV screens. And almost 15 years since the Bundy clan took their familial misery off the air. But the casts of both shows will soon be reuniting to celebrate an even more surprising milestone: the Fox network's first 25 years on the air.

"Fox's 25th Anniversary Special" is set to air April 22 and will include appearances from David Duchovny and Gillian Anderson of "The X-Files" (along with creator Chris Carter) as well as every member of the Bundy house: Ed O'Neill, Katey Segal, Christina Applegate and David Faustino.

In addition, some of the original "Beverly Hills, 90210" cast will appear, including Shannen Doherty, Jason Preistly, Ian Ziering and Gabrielle Carteris. Ally McBeal herself, Calista Flockhart, and The Tick, Patrick Warburton, will also appear.

Fox expects to announce more actors and a host in the weeks ahead. The special will be executive produced by regular Emmy producer Don Mischer and Charlie Haykel.

Fox first broadcast on April 5, 1987. It was the fourth network after a long domination by the other three (ABC, CBS and NBC). This season it's ranked No. 1 in the 18-49 demographic.

Among the shows in its intial lineup were "Married ... With Children," "The Tracey Ullman Show" (which gave birth to "The Simpsons"), "21 Jump Street" (starring an unknown named Johnny Depp), "Mr. President" (a comedy starring George C. Scott and co-created by Johnny Carson), the sitcom "Duet," the horror series "Werewolf," the comedy-adventure series "The New Adventures of Beans Baxter," the Patty Duke comedy "Karen's Song" and a TV version of the hit movie "Down and Out in Beverly Hills" (which was also the first series Fox ever canceled).