The .exe links are installers and the .zip links are self-contained "portable" archives.
Unzip and read readme.txt for installation. These work for 0.9.5 as well.
The manual (up to date for version 0.9.5) is online here: Kinovea manual 0.9.5.
It can also be downloaded for offline use here: Kinovea-Manual-0.9.5.zip
The old manual for version 0.8.15 is here: Kinovea manual 0.8.15
Translations of the user interface are contributed by users like you. To help with the effort go to the Kinovea translation project at Weblate.
Kinovea is a free software under the GPL v2 license. Please have a look at license.txt in the installation directory for more information.
You can use it for free for any purpose, including personal, academic or commercial. You do not have to ask for permission to use it in your research, university courses, bike fit shop, physical therapy clinic, or any other business or hobby activity.
The source code for Kinovea is versionned using git and hosted on github.