In some cases, the best way to illustrate something happening on your screen is to show someone. Whether you want to train people on a particularly difficult program or show everyone how to fix a problem you've run into before, recording a screencast is an easy way to do it. Thankfully, there are plenty of applications that let you record your screen, save the video, and share it with friends.

Screencasting or screen recorder software classified by operating system: Windows, Mac and Linux.

Recommended screencasting software for Windows

Recommended screencasting software for Mac

Recommended screencasting software for Linux