Online video destination Hulu will carry Joss Whedon’s popular Web musical “Dr. Horrible’s Sing-Along Blog” for the next four months, the site announced today.

Hulu said the show, which stars Neil Patrick Harris, will be available exclusively on Hulu and its distribution partners, including AOL, MySpace, MSN, Yahoo and Comcast.

The show was first offered earlier this month in three parts on DrHorrible.com, Hulu and iTunes, where it has consisently ranked among the top downloads on the service’s TV menu.

Mr. Whedon authored a blog post today on Hulu about his show.