Joss Whedon’s made-for-Internet tuner “Dr. Horrible’s Sing-Along Blog” was a little too popular in its debut late Monday night.

First installment of the three-part program — starring Neil Patrick Harris, Nathan Fillion and Felicia Day — bowed at 10:30 p.m. PST as a paid $1.99 download via Apple’s iTunes or free Web streaming via Drhorrible.com. Shortly after midnight, the Dr. Horrible website crashed under the punishing demand of some 200,000 hits per hour. “Dr. Horrible” also ranked No. 1 on iTunes TV downloads for most of the day Tuesday.

Whedon’s brother Jed spent the wee hours of Tuesday morning lining up a much bigger server to handle the traffic, and he dealt with encryption issues that were preventing Joss Whedon buffs in Oz and other offshore locales from accessing the content. The Dr. Horrible site was back up and running by early ayem West Coast time.

Second installment of “Dr. Horrible” is set to bow Thursday, with the concluding seg bowing Saturday. The entire program will be available for free streaming through midnight Sunday and through July 29 on iTunes. Given the program’s splashy debut based only on word of mouth and Internet buzz, Whedon’s reps are lining up a soundtrack release deal and a DVD distrib deal.

Whedon will also promo the project with a midnight screening later this month at Comic-Con.

Joss Whedon financed “Dr. Horrible” on his own from an idea hatched during the writers strike based on his interest in testing the waters for made-for-Internet content. Program was written by Joss and his brothers Jed and Zack Whedon and Maurissa Tancharoen, who is a writer along with Jed Whedon on Joss’ upcoming Fox drama “Dollhouse.” Joss Whedon directed “Dr. Horrible.”