U3 (software)

U3 refers to an application design specification created for Microsoft Windows operating systems so that applications can be executed directly from a specially formatted USB flash drive. Applications are allowed to write files or registry information to the host computer, but this information must be removed when the flash drive is ejected.

USB flash drives adhering to the U3 specification are termed "U3 smart drives" by U3.com. "U3 smart drives" differ from traditional USB flash drives because they come preinstalled with the U3 Launchpad, which emulates the Windows OS start menu, and controls program installation.

The U3 Platform

U3 Launchpad

The U3 Launchpad is a program manager that is preinstalled on every U3 smart drive, and is set to autoplay on insertion. [1]

The program is made to work with Windows 2000 Service Pack 4 and above. No Launchpad program exists for the MacOS or Linux platforms. [2]

U3 Applications

To be fully U3 compliant, an application has to be programmed with portability in mind; furthermore, it must be packaged in a ZIP archive with an XML file that tells the U3 device how to execute the program and what to display in the U3 Launchpad. [3]

APIs

The U3 APIs allows U3 Programs lower-level access to USB flash drive.

Hardware

U3 smart drives are traditional USB flash drives with a specific setup:

• Two partitions: one for the U3 Launchpad, and one for U3 Programs and Data.
• U3 Launchpad Preloaded onto primary partition and set to autoplay
• Optional: U3 Compliant Applications Preloaded

Hardware manufacturers can get the hardware development kit by emailing licensing@u3.org. [4]

Compatibility

The U3 Launchpad and U3 Applications will only run on newer Microsoft Windows Operating Systems (Microsoft Windows 2000 with Service Pack 4 and Windows XP). Data will continue to be accessible from any OS capable of reading from USB Mass Storage Devices.

Developer Resources

Information on building U3 compliant applications, and the U3 software development kit, are available to registered developers at the official U3 website. Individuals must register (as a company) to download the SDK, or participate in the forums. [5]

Other uses

Hobbyist PlayStation Portable Applications

The U3 platform may be a target for PSP hobbyist applications as it may be possible to access folders within U3 using the PSP, thereby allowing application usage away from a proper computer.

See also

• USB
• USB flash drive
• List of portable applications

External links

Official

• U3 website
• U3 Knowledge Base
• U3 Software Central
• ExtreMemory An European manufacturer of U3 hardware

Reviews and Overviews

• U3-Info : U3 Community site with news, resources, articles and forums
• PC Magazine reviews the U3 Launcher, and programs (has screenshots)
• Freeware site applauds the simplification of "portable" application development
• U3 Newbie Guide

Developer Resources

• U3 SDK (requires registration. individuals can register as companies)
• U3 Platform Overview (pdf)