When managing applications with many tables (and the number is actually 750+ for the application I spend time on every working day), keeping it all in your head -- the tables, their relations, and the rules for those relations, the field specs for common fields throughout the schema -- is not a possibility for all but the most gifted. For the rest of us, having a tool that allows us to lay out those relationships diagrammatically is a necessity, not a luxury. xCase is, quite simply, the most productive ERD (Entity-Relationship Diagramming) tool we have found, in the 20 years we have been using it.
We integrated it into our VFP work, and are now integrating it into our Lianja work.
You don't need xCase to work with the PSP4Lianja metadata system. You will, however, be many hours more productive per week by using xCase if you are working with new or updated schemas on a regular basis. If you work with only one data model of modest size, and it hardly ever changes, you don't need it.
We get nothing in return for your use of xCase. We pay for our use of xCase, just as you do.