Comcast announced today it is launching Stream, its own internet TV service. The $15-per-month service will be available to Comcast’s Xfinity broadband customers and launch in Boston at the end of the summer before being made available everywhere in Comcast’s footprint by early 2016. By offering it in areas where only Xfinity is available, Stream will not — initially at least — be available to non-Comcast users. The service will offer a dozen networks via laptops and mobile devices, including the major broadcast networks and HBO. It will also offer on-demand content and a cloud-based DVR.

“We want to make ordering Stream as easy as buying a song online. And make tuning in to a show as simple as opening an email,” said Matthew Strauss, EVP and GM of Video Services for Comcast Cable. “We’ll continue to experiment by creating offerings like Stream, so that users can choose the service that works best for them. So if you love TV and spend most of your time with the screen in your lap as opposed to the one on the wall, Stream may just be the thing for you.”

That last comment was another way of saying that customers won’t be able to view Stream on their TV sets, at least not without a work-around. It also won’t offer premium channels other than HBO, and such popular channels as AMC.