As customers became more confident about open source licensing, dual-license schemes became less popular, so many vendors switched to an alternative model. While creating a "community edition," they also created powerful "enterprise" features -- backup, load balancing, instrumentation, interoperability with proprietary systems -- and sold them under proprietary licenses.
The problem with this approach is obvious. While the vendor is indeed working on and making valuable contributions to the fully open source community edition, the capabilities customers need are actually proprietary and deliver none of the flexibility and control that open source offers.
As long as the enterprise features aren't critical to you, it's still possible to retain your software freedom -- just use the community edition and get your service and support from the group. Many businesses use the community editions of open core packages as an explicit part of their IT strategy.
Commercial open source
Since it's so easy to do, open core vendors increasingly blend together access to subscriptions and support with a requirement you use the "enterprise edition," perhaps even under full proprietary licenses that restrict your freedom to leave. The unfortunate term sometimes used to describe this blended model is "commercial open source." Don't let this deceptive phrasing confuse you.
Check that you are the beneficiary of the four freedoms that open source guarantees, rather than just your vendor. If the software freedoms stop with them, you don't have the flexibility of open source to control what software you use, not to mention how, when, where, and with what level of support. Instead, you are handing control of your IT budget to your vendor with just as much certainty as any other proprietary software.
Practice safe selection
There's nothing wrong with using open source software within commercial solutions. After all, a basic requirement of the open source definition is the freedom to engage in commercial behavior with open source. But if software freedom stops with your supplier, it's deceptive to say you're somehow the beneficiary of open source. If having open source embedded within proprietary systems was all it took, pretty much everything Apple, Microsoft, Oracle, and IBM make could be described as open source. My test: if my relationship with the vendor ends, can I still use the software?
If you encounter a vendor claiming its solution is "open source," yet not delivering software freedom, what should you do? If you have another choice, take it. If you don't have a choice, use the hints I've included here to isolate the proprietary elements from the open source elements as much as you can. Remember: It's not open source to you if it doesn't deliver software freedom.
This article, "Beware these three open source lock-in schemes," was originally published at InfoWorld.com. Read more of the Open Sources blog and follow the latest developments in open source at InfoWorld.com. For the latest business technology news, follow InfoWorld.com on Twitter.