Day I think there are a lot of the things that Hollywood doesn't understand about the Internet. It's kind of the reverse of mainstream media: You don't want to aim for everybody. You want to aim for a targeted audience, and then from there, that passionate audience is going to spread the word. It's a different approach to creating something for the Internet, and clearly, Joss's got it. Dr. Horrible was all word-of-mouth.

Though the free streams ended July 20, Dr. Horrible remains available as a paid download on iTunes, with a DVD release (packed with bonus features) planned before the end of the year.

Jed Whedon Joss comes every day with a new extra. So we've got lots of plans; how many we execute is still up in the air.

Joss Whedon We're not sure that we can accomplish it, but we want to have languages: French, Spanish, Japanese translated back very badly into English, classical Latin, and panther noises. That's what we're hoping for. We'll definitely be doing an original musical commentary.

Tancharoen With all of us singing.

Joss Whedon All of us, and all of the actors, and anyone else who has something to sing about. We've been writing that on the side, and it will run the length of the thing as an actual commentary, but it is an all original musical. It's Commentary!

Tancharoen As you can tell the fun doesn't stop for us.

And, yes, there may be a sequel.

Joss Whedon We were approached before it was a hit, people who wanted to talk about the idea of a feature-length film, a sequel, a Broadway version — which we talk about all the time. It wasn't just ''Oh! You might have made money so perhaps I should talk to you.'' It was really a response to Dr. Horrible itself, which was cool. We have played it close, because we want to do it our way. We're taking it sort of one step at a time and usually it's a step too late.

Harris As it was pitched to me initially, they did have this big master plan that might have included the sequels, and the TV films, and the Broadway musical, and the theme park attractions. And the blimp.

Joss Whedon It did start out as kind of a political statement. As we got into preproduction, and the strike was over, it was more about ''Okay, we didn't have our chance to make a bold statement, but we still have our chance to make this.'' And now it's sort of come full circle because people are talking about it as an Internet event, as a business model, as all the things that we had hoped for back when we were still carrying our picket signs. We believe, yes, it will be profitable. It's not I am Legend, not bang out of the gate, ''Woohoo! Studios take note, we've all become billionaires in 30 minutes.'' More just like it's just going to keep going until, yes, we can pay everybody off and then there might be a little more there.

Fillion It's a brand new deal. The people who created it are the people who are in control of it. It's such a weird thing, an incredibly cool thing. I think a very interesting peek at how I think things are going to start to be: the future of entertainment, I believe.

(Additional reporting by Jeff Jensen and Dafna Pleban)