The move goes significantly beyond the current access to YouTube videos in which any web user can copy and embed selected videos onto their own web pages.

YouTube said its latest customisation offerings allow anyone building a website or Internet-connected software program to upload videos straight to YouTube. They can fetch video feeds, comments, responses or playlists from YouTube.

What YouTube is offering parallels an earlier move by Yahoo Inc to open up the ability of its Flickr photo-sharing site to provide deep access to web developers in order to embed underlying features of Flickr in other sites.

Web site developers can let users rate videos or add them to a favourites list embedded within their own sites. They can also customise and control the Adobe Systems Inc Flash video playing software through which videos are viewed.

The expansion of what is known in technical jargon as APIs, or Application Programmer Interfaces, lets developers build a so-called "chromeless" Flash player, a video-viewing window that is stripped of formatting such as title bar, browser buttons or status bars so they can create their own players.

These free customisation features can be used in conjunction with the existing APIs which launched last year and which provide the ability to view videos on other sites and to search for videos on YouTube.

By adding underlying features and functions of YouTube, developers can enable users to publish videos directly from their mobile phone devices or encourage new users to share videos to the website, as if they were on YouTube itself.