A large collection of GNU and Open Source tools that provide functionality similar to a Linux distribution on Windows.It's a pain to write bash scripts that work on Linux, on Macs, and on commercial Unices, and then have to jump headlong into PowerShell and batch files to attempt to match the level of automation that I can achieve with some Bash scripting.
I've used it for years to homogenize my environments into one where I can write scripts once and deliver them everywhere for consistent automation solutions. If you've never heard of Cygwin, you're in for a treat.
