Why Open Source

Customer is in control. The Internet enables the application to be developed under the design control of multiple collaborating customers.
The customer can extensively test the application for its fit to his business before making any extensive and expensive commitment to it.
High quality applications - massive peer review assures reliability and security.
Open and widespread standards - there are no secrets in open source software.
Wide source for developers - It takes advantage of the Internet for worldwide collaboration and expertise.
High quality maintenance and customization service. Service is the only marketable product and the customer chooses the provider of service.
Development and support costs are distributed among multiple companies.
No vendor lock in - lower implementation and switching costs.
Can evolve with the customer's business no matter what happens to the original developer or developers.

Vendor is in control. The application is developed for the financial and business benefit of the vendor. The customer is a means by which the vendor achieves these benefits.
Expensive to develop - industry averages are 10 to 15 lines of code per day per developer. Total costs average out to about $50 per line of code.
Vendor Lock In - The customer is dependent upon the developer or 'owner' of the software for enhancements and service.
Low reliability - Proprietary software is notoriously 'buggy'.
Low functionality - Proprietary software is notoriously only 'partially satisfactory'.
Low security - Few eyes see the code. Software 'holes' remained unfixed.
Duplicate efforts - For each business function there are numerous software packages developed by numerous small pockets of independent developers.
Difficult to communicate or share data between systems. Standards, protocols, and algorithms are kept secret as 'intellectual property'. 'Open' standards are 'closed' by proprietary extensions for business advantage.
Narrow source for developers. Vendors are dependent on their own 'in-house' expertise.
Package marketing - Competition is on the selling of a 'package'. Service and enhancements, and maintenance are considered necessary overheads.