win and mac

I'm writing this post cause it took me much time to find some free softwares that can record activities from screen for Windows and Mac systems. I use both OS at office and lab.

I'm doing some experiments. One is to measure the deformation of microcapsules, both loading curves and deforming capsules via a light microscope displaying on the screen; another is to observe the movement of nano/microcapsules in a cell. For both cases everything is displayed on the screen. I want to record them for kind of live show without using any external recorder and then converting clips.