To provide information about the physical resources, books status, and locations most of the libraries in the world now a days are using web OPAC. Keeping in view of the same the IOU Libraries established Web OPAC for its libraries which are accessible from anywhere through Cell Phones, Laptop and Personal Systems. The IOU Library OPAC provides to find out the status, locations and availability status of library physical books. Library catalogue is perhaps the most important tool for locating material in the Library. The IOU Library Union OPAC provides access to the catalogue through a computer terminal. OPAC allows searching the entire catalogue online, conveniently and quickly, using one or more search criteria. One can, for example, search by author, title, keywords, class number or one or more of these combined together. OPAC even shows the current status of a book, whether it is loaned out, available on the shelf or lying elsewhere. Another advantage of OPAC is its ability to display catalogue records in a variety of formats such as AACR2, MARC, etc., and the records can be displayed in a desired order. Web OPAC can be searched using any common browser, such as Microsoft Internet Explorer or google chrome.