MSSP is offered in two versions: MSSP Applet (Java applet) and JS MSSP (HTML5 with JavaScript). For the applet version, the only essential requirement is the Java Plugin (most recent version is advised), nothing else. On the other hand, the JS version solely depends on JavaScript and therefore does not require Java installation.
Important Note: as Chrome has recently stopped supporting the Java Plugin, we recommend running MSSP Applet on the most recent Firefox version.
In order to run the MSSP applet version properly, first you have to configure accordingly your Java plugin security settings:
More detailed information on how to configure the Java plugin security settings can be found here and here.