Grooveshark is a very popular online service which allows you to listen to popular songs across the world using the online player. You can search for songs (MP3) and then listen to it using the web player. You can also create free account and then create playlists. Grooveshark Desktop is a simple application which does the same job as the online service, but does not require any web browser. It is a standalone application which connects to internet and does the streaming.
You can even log in your account and then create playlists and also save them for playing it later.
Related: Download Music from Grooveshark with Downloader
This Windows application was developed to be small program that will enable users to access Grooveshark service directly from their desktop, without the need of a web browser.