Google's YouTube, one of the jewels of the participatory Web, just got a lot more open.

The world's most popular video site announced today that it is offering new application program interfaces, or APIs (define), that will enable developers to access the YouTube database and embed video content on their sites.

"For partners and developers, YouTube has grown into much more than a Web site," YouTube product manager Jim Patterson wrote in a company blog. "It has become an open, general-purpose video services platform, available for use by just about any third-party Web site, desktop application or consumer device."

The announcement builds significantly on YouTube's previous APIs, which allowed users to search the database and upload select videos onto their sites. By offering its technology and entire video content to other Web sites, YouTube is now positioning itself more as a video-serving platform than merely a destination for people to come and watch content.

The move comes as Google (NASDAQ: GOOG) has been moving aggressively to monetize video content by broadening the YouTube partners program and expanding its AdSense program to include video placements.

Now, YouTube's ad-enabled videos will find a wider audience as more developers begin integrating them into their sites.

In addition, users will have access to the complete YouTube library, with a full set of create, retrieve, update, delete (CRUD) persistent storage capabilities available to manage the content.

In opening access to its database functions, YouTube is giving third-party sites the opportunity to tap its streaming and hosting services to reach its considerable global audience.

The new APIs will enable developers to create "chromeless" Flash players with a customizable interface built on YouTube software, but without the YouTube branding. Instead, YouTube is asking developers to place a "Powered by YouTube" button on the pages of their sites that contain the API-enabled video players.

Developers will be able to upload videos and responses to YouTube from any device, including cell phones and other handhelds. The APIs will also allow developers to augment the video content on their sites with metadata, such as titles, descriptions, ratings and comments.

YouTube is enabling third-party sites to retrieve feeds set to the specifications of 18 international locales. With this feature, developers could create feeds that regularly fetch the top-rated or most-viewed content on YouTube from a particular corner of the world where their audience might be concentrated.

Among the early adopters of YouTube's APIs is TiVo, which is integrating content from the site into its DVR service so that people can watch, rate and share YouTube videos on their television sets.

Meanwhile, the University of California, Berkeley, is using the upload API to publish lectures and other video course material to YouTube, and video game publisher Electronic Arts allows players to post and share videos on the site incorporating characters they've created in its forthcoming game Spore.