A mechanism for delivering full-blown Java applications from a Web server. The programs are initially downloaded using the browser but are run outside of the browser. Contrast with Java applets ...

Alternatively, the user can start the application from a link on a web page that points to the same URL/JNLP file combination; i.e., the original version from the website.

Since JNLP files are simply Java Web Start files that open applications through an Internet browser, any browser that works in Windows 8.1 will open a JNLP file as long as you have Java installed.