Audacity was developed by a group of volunteers under the GNU General Public License (GPL), and is open source, or free software. This not only means that it does not cost anything to download, but also that you can use the program, create items with it, and freely distribute these items, modify the program itself, and share your work with others.
You can download Audacity for:
Let's briefly go over how to download and install Audacity.
The installation process for both of these operating systems is similar: