Indeed yes, individual companies will upload the FMS database with their own company routes, SIDs and STARs. Naturally, each airport have their own approach procedures, so not all airports will have a published FMS STAR. Major carriers have their own route navigation departments who are responsible for defining/editing either a recognised software package (such as Jeppesson), or for compiling their own software. There are strict regulations in force to ensure that these departments are approved by the regulatory authority... remember the Mt Erebus disaster; all because of a wrongly defined waypoint way down there in the Antarctic... all lives lost on a commercial tourist flight; all down to a decimal point! As for private use databases... you're on your own, and, should you not have a nice day because of a wrongly defined waypoint... beware, the subsequent board of enquiry by the regularory authorities will prosecute! However, it's likely that you'll be within Class A airspace and you shouldn't be there without the relevent rating anyway; that's why the regulatory authorities make the rules. That's enough from me. Tarra!