NSV (Nullsoft Streaming Video) is an audiovisual container format for streaming video data online. It was created in 2003 by Justin Frankel, while he was still working for Nullsoft. NSV only supports VP3 video codes and MP3 audio, although it was initially designed to stream all audio and video codecs. It is, in fact, the first format to allow users to make and stream live/recorded videos over the internet.
WMV (Windows Media Video) is a collection of video codecs with their respective coding formats introduced by Microsoft on its Windows Media framework. Initially, it was designed to compete with RM format on online streaming apps. It stores compressed videos and is even used to deliver content on Blu-ray/DVDs.
VLC Media Player MPLayer Media Player Classic Windows Media Player