When comparing Cygwin vs Greenshot (for Windows), the Slant community recommends Greenshot (for Windows) for most people. In the question“What are the best power user tools for Windows?” Greenshot (for Windows) is ranked 13th while Cygwin is ranked 19th. The most important reason people chose Greenshot (for Windows) is:
Greenshot is licensed under GPL with source code available on [BitBucket](https://bitbucket.org/greenshot/greenshot).
Ranked in these QuestionsQuestion Ranking
Pro Additional packages available via Cygwin Ports project
Pro Better default terminal
Cygwin's default terminal "Mintty" is far better than CMD.
Pro You can run graphical applications
It has X Server.
Pro Free and open source
Greenshot is licensed under GPL with source code available on BitBucket.
Pro Can capture an entire webpage
Instead of just capturing the visible portion of the page, this tool can capture all of the page in one image by scrolling through the page, taking images at set points and then stitching the images together.
Pro Allows annotating, highlighting and obfuscating screenshots
Pro Freezes screen when you capture
When you enter a capture mode, the screen content is preserved as it was when you started capturing.
Pro Can be quickly invoked with the print screen button
Pressing the print screen button will allow you to select the captured area.
Pro Classic UI design makes it easy to use.
Pro Selecting custom rectangle is the default
Easy to use selection tool with a magnifier to select only the part of the screen that you need.
Con Many incompatibilities
A lot of tools don't actually work with Cygwin, and documentation is often sparse, so for many use cases, it's worth the small bit of extra effort to just run a full virtual machine.
Con This version only works on Windows, not Linux nor Mac
However, the same author now has a separate version of Greenshot for iOS, which is available (for a small fee) in the Mac App Store at https://itunes.apple.com/us/app/greenshot/id1103915944