Dr Horrible's Sing-A-Long Blog, the offbeat creation of Buffy's Joss Whedon, will be available between July 15th and 20th online before officially premiering at Comic Con.

Conceived by Whedon during the recent Writers Guild of America strike, the hour long "supervillain musical" stars Neil Patrick Harris, Nathan Fillion and Felicia Day. Unlike Whedon's musical episode for Buffy, Dr Horrible is "completely fresh and new. We could tell a story that felt completely complete."

Whedon told The Hollywood Reporter that a DVD release complete with commentary and a "serious" look behind the scenes at the production. The writer also intends to create Dr Horrible comic books.

Dr Horrible follows the titular supervillain, played by Harris and his nemesis Captain Hammer (Fillion) as Horrible tries to get into the Evil League of Evil and win the affections of Penny.

Act 1 starts streaming at www. drhorrible.com on July 15th. Click here for our interview with Joss Whedon and co.