The new tools allow users on other sites to search the YouTube inventory, rate videos, and upload clips to YouTube's servers.
The move marks YouTube's latest step in its transformation from a destination site, to online video application provider.
YouTube will handle the hosting, transcoding, streaming and thumbnails for each video, but will allow the consumer to control the uploading, management, searching and playback of clips.
For web developers, the deal means generous access to YouTube's user base.