(written from a Production point of view)
Jane Espenson (born 14 July 1964; age 52) pitched, and subsequently sold, two story ideas to Star Trek: The Next Generation, one involving warp drive damaging space-time. She then wrote the Star Trek: Deep Space Nine season four episode "Accession". She later went on to be a writer on Buffy the Vampire Slayer, Angel, and the short-lived Firefly.
Espenson also wrote for Ronald D. Moore's Battlestar Galactica in its third and fourth seasons, writing the episodes "The Passage", "Dirty Hands", "Escape Velocity", "The Hub", and "Deadlock", as well as the spin-off DVD film The Plan. She also served as a co-executive producer for the series' fourth season and the spin-off DVD film Battlestar Galactica: Razor, which focused on the Pegasus, commanded by Helena Cain (Michelle Forbes). Espenson subsequently worked as a writer and producer on the Battlestar Galactica spin-off Caprica, and held the post of showrunner for several months during its development and first season; during the first season, Espenson decided to step down to concentrate on writing.
Espenson served as consulting producer on Joss Whedon's fantasy series Dollhouse (2009) and wrote the first season episode Briar Rose (2009).
Espenson was one of the writers for the fourth season of the Doctor Who spin-off Torchwood. This makes her, along with fellow Torchwood writer John Shiban, one of only two people to write for both the Star Trek and Doctor Who franchises on television.  More recently, she has been a writer for the ABC series Once Upon a Time.