The battle to provide free television and movies online has intensified with Sling Media throwing its hat into the ring.

The San Mateo, Calif.-based company, which makes the Slingbox remote television-viewing device, on Tuesday opened up its Sling.com video portal to the public. The website, which features popular television shows including Saturday Night Live and The Office and movies from Warner Bros, Sony and MGM, is going toe-to-toe with rivals Hulu, YouTube and Joost.

The free content, which is only available to U.S. residents so far, is supported by ads that run before and during the videos. Sling has partnered with Hulu, which is a joint venture between Fox and NBC, as well as CBS, PBS, BBC America and a number of web video sites including College Humor and Break.com to provide much of its content.

Sling is differentiating itself by allowing owners of its Slingbox to connect their devices to the website and stream any content saved on it. The Slingbox, which was introduced in 2005, allows users to stream their subscription television service to any computer.

The opening of the website came on the same day that YouTube announced it was offering its video in widescreen format in order to be viewed more easily on television screens. Sling, YouTube, Hulu and Joost are offering increasing amounts of free, advertising-supported television and movie content over the internet.

The websites represent a threat to traditional television service distributors, such as cable companies and satellite providers, by offering the same content for free. The sites are also moving toward making their content more easily viewable on television screens by boosting the picture quality of videos.