42 Interactive digital platform as a service (PAAS) featuring computer software platforms for hosting and rendering e-textbooks including both public domain and proprietary content, resources, and other digital content on global computer networks, wireless networks, and electronic communications networks; providing an online network service that enables users to share content, text, visual works, audio works, audiovisual works, literary works, data, files, documents and electronic works in the field of the sciences, business, marketing, economics, communications, education, mathematics, medicine, music, the fine arts, and the liberal arts; providing a web site that gives computer users the ability to transmit, cache, receive, download, stream, broadcast, display, format, transfer and share content, text, visual works, audio works, audiovisual works, literary works, data, files, documents and electronic works; providing search platforms to allow users to request and receive, content, text, visual works, audio works, audiovisual works, literary works, data, files, documents and electronic works; document data transfer from one computer format to another that enables users to access and share content, text, visual works, audio works, audiovisual works, literary works, data, files, documents and electronic works