Build a Tool which allows USERS TO BUILD A PRESENTATION SLIDE online

Build a tool which allow users to create their own Presentation modules online using all th EDITORS and features which powerpoint offers, Features like adding text, images, cliparts, videos, text animations ( flying text), color additions etc should be available. It should be EASY TO USE for users. PAST EXPERIENCE IN SIMILAR WORK REQUIRED. PROJECT WONT BE AWARDED UNTIL WE SEE A WORKING DEMO.