Goliath Auto Screen Capture is a free tool for taking rapid-fire screenshots. The user can simply select an area of the screen to capture, then use their computer as usual until ready to end the recording.
Native Java utility that easily saves your current clipboard image (or screen image) to a PNG image file on your desktop. No setup or configuration required - just run the jar!
Snap is an OpenSource ScreenShot capturing utility written completely using Java Swing. It has a GUI Version and a command line variant which the user can choose based upon his/her choice. The captured ScreenShot can be saved in either jpg or png format.