Twitter acquired Vine last fall, but anyone can use Vine regardless of whether they use Twitter. However, the service is clearly meant to be embedded anywhere, and there are plenty of examples of the videos being embedded in tweets. The service (see an example below) is being referred to by many as Twitter's "Instagram for video."
Holding hands at Tilden park vine.co/v/biTaEEwdq2n?1— James Buckhouse (@buckhouse) January 24, 2013
Vine videos are limited to a maximum of 6 seconds, and play in a continuous loop. They are shot using the Vine app, and users can choose to have sound on or off, as can anyone who encounters a Vine video in a tweet or blog post. In a blog post, Vine co-founder and general manager Dom Hofmann wrote that, "Posts on Vine are about abbreviation -- the shortened form of something larger. They're little windows into the people, settings, ideas and objects that make up your life. They're quirky, and we think that's part of what makes them so special."
The 6-second limitation on Vine posts appears to be Twitter's new atomic unit for video. A Twitter spokesperson said, "The team tested various video lengths, ranging from about 4 seconds to 10 seconds, as they were building Vine. They found that 6 seconds was the ideal length, from both the production and consumption side."
Twitter, of course, has a long history of determining specific, short-lengths of content. The 140-character limit of a tweet was based on limitations of text messages, but in the years since Twitter's launch, the company has added a large amount of other content to tweets, including photos, video, article summaries, and more, making the 140-character limit -- and the new 6-second limit of Vine videos -- seem somewhat arbitrary.
Although Twitter officially unveiled the service today,when he posted a tweet with an embedded Vine video. What wasn't clear yesterday, however, was whether Vine was going to become Twitter's own hosted video service or if -- as turned out to be the case -- it would be a standalone service that works in conjunction with Twitter, but doesn't depend on it.
There are, of course, other embeddable short video services. One is, a service that calls itself a "Twitter for video" and which lets people shoot videos of up to 15 seconds and then embed them in tweets, Facebook posts, blogs, or elsewhere. (You can also view them directly on the Web.) But Twitter seems to have decided that Vine was a service worth buying, despite the fact that it will allow it to exist independently.
Although Vine was released today for iPhone and iPod Touch, Twitter said that versions will be coming eventually for "other platforms," though it did not specify whether that included multiple platforms or just Android.