What’s your favorite software?

Hello, If we share our software here, it would be a great ides. So post your software here with a brief description and link from where it can be downloaded.
Here is a list of my software.
Browser – FireFox
FireFox internet browser
http://www.getfirefox.com/
Toolbar – Google Toolbar
You can use it to check spellings in web forms,  translate the words from english to other languages, search the internet using the Google.com from any webpage, block pop-ups and for many more things.
http://toolbar.google.com/
Voice Chat – Skype
Skype is a little program for making free calls over the internet to anyone else who also has Skype. It’s free and easy to download and use, and works with most computers.
http://www.skype.com/
Mp3 Music – Winamp
Mp3 music player with lot of features. The this I like about winamp is its skins and custom plugins.
http://www.winamp.com/