Hello, this is my first post. I did search the forums for some answers
I am planning on developing a 'hosted' application that many companies will (hopefully) subscribe to...

Although this application is not related to 'customer relationship management', I need the functionality of SugarCRM to track various 'people' in this application.

Therefore, I will have to customize Sugar to suit my app's needs. I presume custom modules will do the job.

Some of the questions that are bugging me are:
a) I need to support MULTIPLE companies in one single Sugar installation
b) Every Company will have an 'admin' who can then 'create' and 'maintain' many 'users' for his Company.
c) A particular Company's data should not be visible to any other Company. In fact, I dont want Company A to know that even Company B subscribes to my online application.
d) My application will have SPECIAL modules, that need to be *shared* b/w companies. For e.g. If I maintain a list of 'preferred' service providers, ALL Companies in my app should be able to view these providers and be able to 'rate' them and write comments about these providers.

I searched the forums and found out that 'Enterprise' version supports multiple companies in one install.. also, Enterprise version is licensed on a per user basis..

The problem is that i *dont know* how many users will use my app... Further, since my venture is a 'startup' (a.k.a limited budget company), I prefer using the Open Source version and modifying it to support multiple companies.

Has *anybody* done this kind of thing with SugarCRM? Please let me know..