Microsoft has declared its love for Linux. 78 percent of companies report using open source software. Open source code powers billions of PCs, servers, phones and tablets. Does this mean the open source approach to software development has triumphed decisively? As 2015 draws to a close, can we fairly call this the year when open source finally "won"?

These questions lead me to think of an essay published by the political scientist Francis Fukuyama in 1989 called "The End of History." Fukuyama famously argued that the disintegration of the Soviet empire, which was then underway, signaled the end of history as the world had known it for the previous two centuries because it meant that Western liberal democracy had won a decisive, irreversible victory against competing ideologies.

Fukuyama didn't argue that liberal democracy had won out everywhere. That was clearly not the case, since there remained plenty of places that were not liberal democracies. But he claimed that, with monarchism and fascism having long since disappeared, and communism having entered into a fatal tailspin, there was no longer an ideology that could meaningfully challenge the brand of liberal democracy that Western societies, led by the United States, espoused.

The End of Open Source History?

In many ways, open source today looks the same as western liberalism did in 1989. To be sure, there remains plenty of software that is not open source.

Yet the clear and remarkable trend in recent years, as Blackduck's survey showed, has been the adoption of open source software and development practices on a massive scale by companies. Indeed, the use of open source has nearly doubled in just the past five years, underlining how rapidly the tide has turned in open source's favor.

Meanwhile, open source no longer faces meaningful challenges from factions that once wanted to destroy it. Under CEO Satya Nadella -- whose predecessor denounced Linux as a "cancer" and invested millions of dollars trying to discredit open source -- Microsoft has become a friend of the open source community. It now cooperates actively with open source developers, recruits open source talent and has open-sourced an increasing amount of its own code.

Even Apple has become more open with its code. That's notable because Apple -- despite using open source software as the basis for its OS X and iOS operating systems -- has tended to be highly proprietary about its code and has pursued vendor lock-in even more than Microsoft did in the late 1990s. Historically, Apple's policies engendered a fair amount of ill-will between it and the open source community. In 2015, that's no longer the case.

Defining Victory

Before declaring 2015 the year in which open source finally won, it's worth keeping in mind that victory is in the eye of the beholder. The facts that open source is now ubiquitous in the business world, and has made friends with former enemies, should not be allowed to obscure the limitations upon open source's successes.

One limitation is that new computing paradigms have undercut the ability of open source software to assure users the freedoms that free and open source software was originally conceived to protect. For example, open source has become vital to powering the cloud, but cloud-based applications -- even if they run using open source code -- can deny users the freedom to modify or study them, as Richard Stallman has noted.

Similarly, open source embedded devices, which are proliferating as IoT takes off, allow users virtually no freedom to customize or control their behavior. There's a good chance your smart thermostat, wireless router or GPS unit is powered by Linux. But that doesn't mean you can realistically modify its code, or do much to customize the embedded software.

Then there's Android, the Linux-based mobile operating system that has probably done more than any other platform to bring open source software into the homes of hundreds of millions of people since Google launched it in 2007. But that success is clouded by the fact that Google engineers have declared that "Android is not Linux." In addition, Android-based devices usually come locked down and rely on proprietary components to function. That makes Android a poor example of a platform that protects users' freedoms in the way the Free Software Foundation, for instance, would like.

For these reasons, it seems simplistic to say that open source has finally won. It certainly made great strides in 2015. But in some respects, its growth has come at the expense of its original purpose. That's why it's important to continuing watching open source trends in the new year.