There are lots of screen capture apps available for the Mac, but these four stand out in the crows. TechSmith Corp.’s Camtasia for Mac as screen-recording, or screencasting, software. Voila, an image capturing, annotating and sharing tool that boasts the ability to capture a region from the screen in rectangular, circular, polygonal or free hand form. ScreenFlow from Telestream calls itself “professional screencasting studio” for Mac OS X. And, Snapz Pro X from Ambrosia Software allows you to record anything on your screen, saving it as a QuickTime movie or screenshot that can be emailed, put up on the web or distributed as you wish.