Custom php/database driven intranet application for contacts, correspondence, files and, sold software licenses

I need a custom intranet application for a fairly small company that will allow company employees to: 1) keep track of contacts in a custom structure (company, department, person) 2) keep track of correspondence (with who, summary, files, reminders) 3) keep track of sold software licenses (price, package, to who, sold date and expired date) 4) Document/file archive. Files can be uploaded, downloaded, reuploaded (old versions should be kept available) and deleted This will be run on a Linux server, and should be developed using php/mysql/apache.