Microsoft Agent

Microsoft Agent was a technology developed by Microsoft which employed animated characters, text-to-speech engines, and speech recognition software to enhance interaction with computer users. Microsoft Agent functionality was exposed as an ActiveX control that could be used by web pages.

It came preinstalled as part of Windows 98 through Windows Vista. Microsoft stopped bundling the technology with the OS starting with Windows 7.

The theory behind Microsoft Agent came from work on social interfaces by Clifford Nass and Byron Reeves at Stanford's Center for the Study of Language and Information.

History
Interactive character technology was first introduced in Microsoft Bob, which used an early version of Agent technology internally referred to as "Microsoft Actor." Actor is used for the initial version of the Office Assistant in Office 97.

Microsoft Agent was subsequently created by Tandy Trower in an attempt to offer technology that was more flexible and available to third-party developers to include in their applications and web pages. The software release also included four interactive characters as well as a utility that enabled developers to assemble their own characters and interactions.

Microsoft Agent replaced the original Microsoft Actor in Office 2000, although this did not include Agent's much-touted speech synthesis or recognition capabilities or any of the four Microsoft Agent characters. Instead, the Office team created their own characters including one dubbed "Clippit" or "Clippy". However, Bob Actors or Office 97 assistants are incompatible with Office 2000 and later versions, and vice versa.

The current version of Microsoft Agent was quietly released on MSDN in 1997, and is bundled with the installation media of Internet Explorer 4. While the original release of IE 4 included version 1.5, the installer for IE 4.01 SP2 includes version 2.0. It is also included in the Office System Pack of Office XP for Windows NT 4.0 and Windows 98.

Overview
Microsoft Agent characters are stored in files of the .ACS extension, and can be stored in a number of compressed .ACF files for better World Wide Web distribution. Microsoft Office 97 and Microsoft Bob Actor characters are stored in files of the .ACT extension.

The speech engine itself is driven by the Microsoft Speech API (SAPI), version 4 and above. Microsoft SAPI provides a control panel for easily installing and switching between various available Text to Speech and Speech to Text engines, as well as voice training and scoring systems to improve the quality and accuracy of both engines.

Microsoft provided four agent characters for free, which could be downloaded from the Microsoft Agent website. These were called Peedy, Merlin, Genie, and Robby. Some characters also shipped with Microsoft Office up to version 2003 as the Office Assistants and with Windows XP as search assistants. New Agent characters could also be created using Microsoft's development tools, including the Agent Character Editor.

Agents could be embedded in software with Visual Basic for Applications and in web pages with VBScript, and automated tools for the purpose of simplifying this exist. However, web page agents are only compatible with Internet Explorer, since alternative browsers like Opera or Mozilla Firefox do not support ActiveX. Additionally, users of Windows Me, Windows 2000, Windows XP and later or owners of Microsoft Office 2000 and later are the only ones who have the software pre-loaded on their computers; others have to download the software and install it manually.

Discontinuation
In Windows Vista, Microsoft Agent uses Speech API (SAPI) version 5.3 as its primary text-to-speech provider. (In previous versions of Windows, Agent uses SAPI version 4.) Multilingual features of Microsoft Agent under a particular language version of the OS are not supported and Microsoft Agent still functions in other languages only under a localized Windows version of the same language.

Microsoft announced in April 2009 that all Microsoft Agent development and support would be discontinued with the release of Windows 7. Microsoft also ceased offering licenses and distributing the SDK to developers.

However, due to customer feedback, Microsoft provided an installation package of the Microsoft Agent core components for use on Windows 7. The download supports SAPI 5.3 compatible speech engines, and also contains the character “Merlin”, which shipped with Windows Vista.

It is possible to restore Microsoft Agent functionality on Windows 8 and later by downloading the components from Microsoft's website. However, the normally transparent space around the Agent becomes solid-colored pink, blue, or green.

There are still third-party websites where users can still download Agent characters from despite the technology being discontinued.