. This paper describes an online database application for Old Slavonic texts, designed for The National Library of Serbia. Its purpose is to present cultural heritage, consisting of medieval Old Slavonic manuscripts, online. It allows the user to perform searches of Old Slavonic text content and view images of original manuscript pages simultaneously, as well as translations and basic manuscript info. It is a system that consists of two database applications, one for data preprocessing, and the other one, for online data display. The first application (“PrePis”), is a desktop application with user-friendly interface to be used by average user with ease. Its purpose is to enable easy gathering and preprocessing of manuscript page images and texts written in Old Slavonic. It was created in FileMaker software. After preprocessing, gathered data is uploaded to the web server that houses the second application and MySQL database. This second application, is a designed for web use. It communicates with online users and MySQL database, by accepting search requests from users, fetching the requested data from the database, generating html pages and sending them back to the online user. It was written in PHP programming language. It can be accessed at: http://digital.nb.rs/rukse