While many developers focus on a single stack for much of their career, I am more of a generalist. I have always loved learning new languages. Over the years, I have worked professionally in C++, C#, PHP, Java, and VB/VB.NET. For personal projects, I've focused primarily on Ruby and Python.
There is value in becoming an expert in a certain stack, but I also see value in experiencing what others have to offer. Being able to hit the ground running using one stack is great when starting a new job, but having experience with a wide array of options makes it easier to choose the right tool for the job.
The languages I've frequently used recently in are Ruby, Python, C#, VB.NET, and Visual Basic 6. Yes, really, lots of VB6 over the last two years.
I have done a little iOS development in RubyMotion, Objective-C, and Swift recently. I plan to continue developing on iOS and possibly branch out to Android.
I know my way around Windows Server fairly well, but I'm much more at home in the UNIX world. At home, many of my servers run FreeBSD, but my production servers elsewhere run Linux.
I'm a strong believer in modern development practices. At work, I've pushed for good code organization, testing, and documentation.