InfoWorld editors and contributors pick the top open source software for data centers, clouds, developers, data crunchers, and IT pros

Whenever you hear someone complain about developer productivity, just slap them. Having slogged through hundreds of open source projects each year for the past several years, I can assure you that developers are extremely productive. Every time we put together this package -- InfoWorld’s annual Best of Open Source Awards, aka the Bossies -- I end up wishing developers were just a little less on the ball.

Of course I had help. InfoWorld is fortunate to draw on many contributors who work as software developers, systems integrators, data scientists, security consultants, and networking gurus in real life. If there’s an open source tool in their domain they don’t already know, they’re eager to dive in. Thanks to the hard work of these experts, our 2015 Bossies encompass some 100 winners in six categories:

Among the major clouds offering mobile back ends as a service, InfoWorld judged Microsoft’s to be the

Where do we find all of these winners? We hang out in the places that open source gathers. We take in the conferences, we hit the meetups, we climb the mountains of open source known as GitHub and Sourceforge -- and the hill of open source, CodePlex. (RIP, Google Code.) We never miss OSCON, and wherever we go, we keep our eyes and our ears open. When a leading light such as Joyent’s  (RethinkDB, recently), we zero in for a close look.

Some winners are inescapable.  has stolen every show that developers have attended for the last 18 months. And the Docker vortex has drawn a number of other new projects into the mix, as containers spark some radical rethinking of the operating system, the structure of applications, and how to monitor and manage all of the moving parts.

Other winners, like , sneak up on us. Just when you begin to think some part of the technology landscape is settling, a new project emerges to shake it up again. RethinkDB is one of a number of young projects that suggest there is much more to come in the world of postrelational databases.

We had no illusions that the Hadoop ecosystem was stabilizing, and sure enough, big data continues to explode. A number of new data analysis projects make their Bossies debut this year, some of them friends of Hadoop and some not. More real-time approaches to distributed data processing are kicking MapReduce to the curb, and for the first time since 2012, Hadoop itself is not among our winners.

Dev tools, databases, desktop apps, apps to run your business -- free, professional-grade software is falling from the sky. All you have to do is pick it up and use it. Open source licensing and the collaborative efforts of countless development teams (and the companies that employ them) are fueling an incredible boom in business software development. With our 2015 Bossies, we offer a guide to the best open source projects the boom has produced.