developer licence

[mohammad_gheysari&yahoo.com]

Hi,
we have purchased Aggregate with a license from your partner in Iran and now is running in the production environment.
you mentioned in your documents to use separate servers for development, test, and production.
for customization and adding new features as plugins to Aggregate, we need developer license for developers to apply on the development server.
how to get for developer license or something similar?
Thanks
Bagher