PortableApps.com is a website offering many free, commonly used Windows applications that have been specially packaged for portability. These portable applications can be used from removable media such as USB flash drives. User data is stored in a subfolder, allowing the user to upgrade or move the software without affecting the data. To remove the software, a user can simply delete the main folder.
The site was founded by John T. Haller and includes contributions from over 100 people, including developers, designers and translators.