1. A Web-based system for accessing development components, which include an online video clip library and an online music clip library, and enabling online production of custom-integrated media products, said system comprising at least one computer server connected to a computer network, said server including: an upload engine capable of receiving over the computer network a plurality of video and music clips from a plurality of content provider users; a storage engine capable of storing the uploaded plurality of video and music clips provided by said plurality of content provider users in a database and media content storage devices as libraries; a search engine capable of indexing the database and media content storage devices that store the libraries of uploaded video and music clips; a user interface engine capable of providing over the computer network to a plurality of producer users interactive Web formatting screens allowing said producer users to select from said libraries a plurality of video and music clips from among any of the video and music clips uploaded by said plurality of content provider users; and a mixer module capable of allowing said producer users to edit and play said selected video and music clips, wherein said mixer module supports mixing together a plurality of said uploaded video and music clips, such that producer users are able to self-produce video advertisement templates each comprising static content and at least one placeholder, said mixer module further capable of allowing advertiser users to customize said video advertisement templates by uploading a list, such that advertiser users are able to automatically self-produce a set of different customized video advertisements based on an advertisement template, in which the at least one placeholder for each customized video advertisement contains a different item from the list, wherein said mixer module is capable of arranging said video advertisement templates and customized video advertisements as respective XML files on a server, said XML files being accessible by a plurality of users using respective browser applications, such that upon updating an XML file representing a video advertisement template or a customized video advertisement, the updated video advertisement template or customized video advertisement is made accessible to users accessing the updated XML file; said system further comprising a Web application for encoding and formatting video advertisements in particular formats.
21. The system of claim 1 , further comprising: a purchase module capable of allowing said advertiser users to purchase said customized video advertisements; and a revenue-sharing module capable of distributing revenue among content provider users and producer users associated with the video advertisement template used in said customized video advertisements.