The ITL file extension is associated with various programs and software packages. One of these programs is iTunes. iTunes use the ITL file t store music database information in the file. Another program called Reliability Analysis ITEM Toolkit use the file extension to store important application information therein. Even a sports prediction betting application called IntelliTipster which was developed by IntelliForecast Labs use this file extension to store information regarding the application. This means that this file format is a proprietary format that is used by respective programs and would only work with these specific programs.
For Apple iTunes, the file name is usually iTunes Library.ITL. The file serves as a database the stores multimedia information such as songs, playlists, ratings, comments and other information that either comes with the saved songs or inputted by the user. When a user deletes this file, Apple iTunes will automatically generate a blank copy of the same filename.
ITEM Toolkit on the other hand uses the file to store project files and libraries for its main functionality which is to predict product consistency and reliability and to achieve optimum product design process. This is the same case with IntelliTipster wherein it uses the ITL file to store sports team performance to generate statistics and therefore predict outcomes of future games.
As this file is proprietary to the program that created or generated it, it can only be accessed or edited by the same program that created it. Though anybody can see the content of the file by any text editor but it might contain information or characters that cannot be understood by a human mind.