|This article relies on references to primary sources. (February 2013)|
|Developed by||TWAIN Working Group|
|Initial release||February, 1992|
|Latest release||TWAIN 2.2 / February 16, 2012|
TWAIN is not a hardware-level protocol, it requires a driver called Data Source for each device. 
The latest version of the TWAIN standard is TWAIN 2.2, released on February 16, 2012. TWAIN 2.2 features include Self-Certification and the white papers for Mandatory Features and Capability Ordering incorporated into the body of the TWAIN Specification. Data Sources advertise the DG / DAT operations they support. A single chapter defines the entire symbolic and numeric space for the TWAIN 2.2 Specification. Constraining a capability is now distinct from the ability to get, set and reset its current value. References the Sample Code for Applications and Data Sources. New definitions added for multiple color dropout, double document detection, negotiable image segments, greater control of warning and error dialogs from the data source, paper handling, printing and the ability to detect both busy and locked data sources. TWAIN Working Group.
The design of TWAIN began in January, 1991. The TWAIN group originally launched in 1992 by several members of the imaging industry, with the intention of standardizing communication between image handling software and hardware. Review of the original TWAIN Developer’s Toolkit occurred from April, 1991 through January, 1992.
The word TWAIN is not an official acronym. The official website notes that "the word TWAIN is from Kipling's The Ballad of East and West — '...and never the twain shall meet...' — reflecting the difficulty, at the time, of connecting scanners and personal computers. It was up-cased to TWAIN to make it more distinctive. This led people to believe it was an acronym, and then to a contest to come up with an expansion. None were selected, but the entry 'Technology Without An Interesting Name' continues to haunt the standard.
Release history 
- TWAIN 1.0, February, 1992 - Initial Release.
- TWAIN 1.5, May, 1993 - Performance Enhancements.
- TWAIN 1.6, February 5, 1996 - Page Length Detect & Buffer Transfer.
- TWAIN 1.7, August 19, 1997 – Production Scanning Features.
- TWAIN 1.8, October 22, 1998 – More production scanning features that were omitted in version 1.7 of the Specification.
- TWAIN 1.9, January 20, 2000 – ICC Color Profiles, Mac Support for Cocoa.
- TWAIN 2.0, February 22, 2008 – Unix/Linux support, check scanning support, open source, 64-bit.
- TWAIN 2.1, July 8, 2009 – Supported on Windows 7 (32 and 64 bit), support for automatic color detection.
- TWAIN 2.2, February 16, 2012 - Self-Certification and Mandatory Features included in the specification.
Vision statement 
The TWAIN Working Group is a not-for-profit organization which represents the imaging industry. TWAIN's purpose is to provide and foster a universal public standard which links applications and image acquisition devices. The ongoing mission of the organization is to continue to enhance the standard to accommodate future technologies.
Objectives of the TWAIN Working Group and standard include:
- Ensure image-handling software and hardware compatibility
- Keep the specification current with the state of current software and hardware while maintaining backward compatibility
- Provide multiple-platform support
- Maintain and distribute a no-charge developer's toolkit
- Ensure ease of implementation
- Encourage widespread adoption
- Open Source Data Source Manager
- LGPL Open Source License
- BSD Open Source Sample Application and Sample Data Source Application
Supported technologies 
TWAIN provides support for:
- Production, high-speed scanning
- ICC Color profiles
- Digital cameras
- Multiple operating system platforms including Windows, Mac OS, and Linux
TWAIN Working Group membership 
Today the TWAIN standard, including the specification, data source manager and sample code, are maintained by the not-for-profit organization TWAIN Working Group.
Board and associate members of the TWAIN Working Group include:
- Adobe Systems, Inc.
- Atalasoft, a Kofax company.
- Avision Inc.
- Dynamsoft Corporation
- Eastman Kodak Company
- Fujitsu Computer Products of America
- JFL Peripheral Solutions, Inc.
- Epson, Inc.
- Hewlett-Packard, Inc.
- InoTec GmbH Organisationssysteme
See also 
- Windows Image Acquisition (WIA)
- Scanner Access Now Easy (SANE)
- Image and Scanner Interface Specification (ISIS)
- TWAIN Working Group
- Overview of TWAIN and TWAIN Data Sources
- TWAIN: Linking Applications and Images - A White Paper by Hewlett Packard
- 9 Rules for Evaluating Web TWAIN Components - A White Paper by Dynamsoft
- ScanTWAIN Open Source Example of using TWAIN 2.0 from Linux
- TWAIN 2.1 specification