Pros:

1. Adopt Technology that can be foolproofed at a wider scale
2. Other people work for you so you don't have to make the product to evolve, therefore you gain IT expertise and enormous savings in investment
3. You are part of a bigger community. So you can also contribute, exchange, discuss to make the Technology better for everyone
4. You learn how to work in an Open Source Project
5. You can create a business from something free if you are willing to specialize your offering around the open source Technology

Cons:

1. License wise, open Source Technology may not be compatible with your commercial strategy
2. If you don't own the product backlog you are not the only one deciding on the evolution of the product
3. There is no “Customer Support”. If it is broken, then either you wait, you fix it yourself or you find a company that provide an enterprise service
4. Malicious code could potentially be introduced without you noticing it since open source is also relying upon a distributed system of trust
5. The project could die tomorrow. No maintainers means you either have to take the project back, or you will be forced to adopt another Technology.

My advice is to always adopt Open Source Technology first, backed by an active community before building and buying anything unless you purposely provide a significant and unique competitive advantage. If it is not your core busines: Asses before Reuse, before Buy, before Build.

Regards, Yannick