While Windows/MS-centric developers (.NET) have their OS decided for them, developers that deploy to Linux environments have a choice as to what their development rig will run. They can run Linux natively (Ubuntu is a good choice) or they can run a setup close to their production setup, but on a Mac. It seems like a recent trend is to move to a MacBook and Mac OS for developing when the target is Linux. Unfortunately this means spending $1,000 or more on your personal hardware. But Chrome OS and a Chromebook offers another alternative.
Using a Chromebook for software and web development has become quite popular. At a mere $200 (the Acer C7 Chromebook), getting your local development machine up and running can be very inexpensive. Check out how @zackfieldman set his up and helped University students avoid spending over a grand on Apple's hardware: Setting Up A Chromebook Development Laptop.