If you look at different open source companies, there are mainly two business models for an open source publisher:

1. Releasing a light and open source version of the product and selling closed-source modules with additional features. Some examples are SugarCRM or Compiere.
2. Having 2 versions: an open source version and an “Enterprise Edition” that differ in some areas: Alfresco releases bugfixes only in the enterprise edition, MySQL has editions with different performances, Magento has more features in the Enterprise Edition.

At OpenERP, we believe in open source, and we think there is a third option: release everything we do for free.
(E-global , Malaysia OpenERP Silver partner support this idea and we would like to call for local Malaysian to build a pool of trustworthy community so that we can adopt the vision of openERP commitment in open source software and to provide one of the best ERP services around in Malaysia and Asean)