There are a couple of indicators of true openness:
- Interoperability: Can the solution be run with any standards-based technology (e.g., browser, app server, etc.)? If you want to move hosting from, say, AWS to Rackspace, what does this entail?
- Active contributors: Look for companies that have committed some significant portion of their technology to the open-source community. This means more than just lobbing code into SourceForge. The real sign is a community of active contributors. For example, how many people have made contributions (features, bug fixes, etc.) to the company’s technology on collaborative development sites like GitHub?
Vendors for whom openness is a part of the DNA offer customers more than just lowered risk of lock-in. There is also the ubiquity of skilled resources, as well as the likelihood of a broader ecosystem. Openness and ecosystems go hand in hand.
See the full story here: http://recode.net/2014/06/04/surviving-technology-extinction/