In order to create a Screencast, you minimally need to use software that can capture the contents (of part) of your computer screen. After having captured a video (plus sound), you might want to do some post-editing of your presentation. But I’ll leave software for post-editing aside for current purposes.
One prominent use case I have in mind is recording the window of a pdf- or power-point viewer. That specific subtype of screencasting is sometimes called slidecasting. The Slideshare site is basically all about slidecasts.
For Windows, CamStudio is a good option for recording a screencast. It’s free & open source. Rather than produce a new guide to its use here, I’ll simply recommend you check out out some relevant tutorials on youtube.
- Tutorial 1 (English, 15:08 mins, Feburary 2013)
- Tutorial 2 (German, 5:16 mins, January 2013)
- Tutorial 3 (German, 9:41 mins, September 2011)
For Linux, there exist several good open-source options. Several of them are likely to be available through your linux distribution’s software manager.
- Tutorial 1 (German, 5:15 mins, November 2012) [This tutorial also shows how to use Openshot-Software to cut/edit videos.]
- Tutorial 2 (German, 4:44 mins, July 2011) [This tutorial shows how to install kazam on the command line. In newer distributions of linux, it will already be waiting for you in the software manager.]
I don’t have a Mac available so the following is just listed for you to try. Mac OS may actually have built-in support via the quicktime player:
Alternatively, you could try screenflow as a test version