Recently I was asked by the IT manager of a customer, also a software development company, what my position was on open source. His developers were arguing in both directions: some characterised open source as being risky due to the potential for people to see the code & discover security vulnerabilities (which really isn't the case) ; other developers asserted that using closed source also had risks such as the vendor being acquired, going out of business, or dropping a particular product line.
My customer wanted to understand if had a "religion" about open vs closed, so I told a story about my perceptions on how closed source & closed systems came back to hurt the company that initiated it....
Microsoft defined the market in the late 1990's: most people couldn't see past the desktop paradigm. Certainly when I was at Sun Microsystems trying to tell people that "the Network is the Computer" I was mostly given blank stares or told I was living in a fool's paradise with the idea of continual network access (now however, some people even suffer from anxiety when they don't have network access). Meanwhile, Microsoft, having been late to the start of the Internet revolution, quickly used its market power to inculcate Internet Explorer as the standard web browser for enterprise customers, so all software using a web interface had to confirm to its particular quirks, and in particular the quirks of Internet Explorer 6. Given this practical requirement, and the dominance of the Windows desktop concept, many software developers would not support their web interfaces with anything else, which in turn meant people had to buy into the Windows desktop world and so the vicious (or virtuous, depending on your point of view) circle continued.
When Microsoft tried to introduce new, better performing versions of Windows and Internet Explorer, however , they found that adoption was poor. Despite their best efforts and despite the end of support life for Windows XP (the last version of windows that supports internet explorer 6), 30% or more of Windows deployments are STILL of this older version, due in part to the huge dependance on the old, closed Microsoft ecosystem of the early 2000's. In other words, Microsoft's own efforts to control the entire software stack actually ended up hurting them, with very poor adoption of Windows Vista, and initially slow adoptions of Windows 7 and 8.
A critical factor here is that these old systems do not work with today's dominant paradigm: mobile computing on phone or tablet. Companies face a potentially huge transitional cost to get access to the way people now access data online. There are a lot of reasons why Microsoft hasn't been as dominant in the mobile space as they'd like to be, but certainly the way they set themselves up at the beginning of the 21st century didn't help.
So how does this fit into the question of open source? Well by definition open source uses standards for data storage & transfer that are open to scrutiny and available for all to use. This means that getting to data and services can be possible from any device or system, not just from some tightly-coupled combination of software systems in a closed box owned by someone else. Companies who developed with open standards in mind found it much easier (and faster) to move to the mobile world.
This is just one reason why open source is important: to provide tools, systems and protocols that can be continuously adapted & developed in compatible ways, rather than head down a one-way path towards a dead end.
A telling footnote to this story is that after many years of decrying open source, Microsoft is now embracing open source as a component of the way it operates, and actively collaborates with open source companies (such as SUSE) to improve interoperability and the effectiveness of their customers' IT environments.
