We are looking to build an internal CRM system and are currently examining tools available in two main categories:
A - "Pure" development platform, for example Access + SQL. Application design (including the data model) and implementation are completely under the developer's control.
B - "You can customize our data model and (seemingly) retain control, but in the end, you are tied to ours". Under this platform, I'm assuming that once you attempt to deploy, you end up paying the license fees as outlined under one of the standard editions (e.g. salesforce.com) in which case it isn't truly free for life as the Developer Edition of salesforce.com claims to be.
I am not certain where developerforce.com falls. After creating a test project with several tables and playing a bit with the Developer Schema, I was feeling confident it fell under category A. Then I had a meeting with my boss who said he suspects it's actually B.
I don't want to go into the details of the application itself and its purpose, as I'm not looking for platform advice. I just want to clarify what we'd be "signing up for" if we decided to undertake the project with developerforce.com.