Let's just say that i want to create a cms + other online applications.

I want them all to integrate into a central location, but they also have to be available seperately (not everyone want's more than the cms solution).

Would i create a huge central application that contains all the database, which communicates through a webserice with the "standalone - integrated" modules?

Or would i create them seperately and the only thing that the "central" application would do is syncing the information (eg. the cms and another solution can have the same tables (eg. clients or employees).

Or do you have another idea? (i know i'm a little vague, but i can't "give" a lot of details because of work - contract).

If someone has all the "packages" it should be possible for the central application to integrate all the modules at one place! Or if someone has more than 1 module, it should combine this on the website.

What i thought is best, is that the central location contains only the users and their rights (eg. cms - all rights, ...), and the information get synced with every change.

(module cms, adding a new client -> store locally and send data to the central location, central location -> send to modules => table clients updated everywhere)

This way it is easy if someone only "bought" a module, they can sync it easily through the complete architecture.

I hope i made myself clear!