This is a list of free application for screen capture that can be installed for free in your computer. Take into account that some of them have restrictions on their use (for example, you cannot use some of them for commercial purposes).
CamStudio
OpenSource
Platforms: Windows
https://sourceforge.net/projects/camstudio/
Requires admin authorization to be installed.
Freeseer
GPL
Platforms: Windows
https://github.com/Freeseer/freeseer
Hypercam v2
Free
Platforms: Windows
https://hyperionics.com/hc2/index.asp
Requires admin authorization to be installed, but it can be extracted as a file and run.
iSpring Free Cam
Free
Platforms: Windows
Not for commercial use.
https://www.ispringsolutions.com/ispring-free-cam
Krut
OpenSource
Platforms: Windows, Linux, Mac.
Java-based. Does not require installation, it is just a JAR file. Not very mature.
Open Broadcaster Software
Open Source
Platform: Windows, Linux, Mac
Screencast Capture Lite
Open Source
Platforms: Windows
http://cesarsouza.github.io/screencast-capture/
ShareX
GPL
Platforms: Windows
VirtualDub
Open Source
Platforms: Windows