Microsoft Agent 1.5

Microsoft Agent 1.5

Screenshot of the Properties menu in Microsoft Agent 1.5.
Name	Microsoft Agent 1.5
Developer(s)	Microsoft
Initial release	September 8th, 1997 (28 years ago)
Latest version	1.5.2.416
Latest version release date	May 22nd, 1998 (27 years ago)
Written in	C++
Operating system	Microsoft Windows
Discontinued?	Yes

Microsoft Agent 1.5 is the first public release of Microsoft Agent, officially released on September 8th, 1997 and made for download on Microsoft's website. Microsoft Agent 1.5 succeeds the previous beta versions made available for developers on the Microsoft Developer Network, with it dropping compatibility for any characters specifically compiled for Microsoft Agent Beta and Microsoft Agent Beta 2.0.

Microsoft Agent 1.5 characters were by default compiled with the .ACF file format, with each individual animation being an .AAF file. However, the user has the option in the Microsoft Agent Character Editor to instead compile the file with .ACS. It is important to note that this version of .ACS is fundamentally different from the .ACS format used in Microsoft Agent 2.0 characters, with the 1.5 .ACS essentially being an OLE Container for the .ACF (which contains all character metadata) and the .AAF (animations).

Microsoft Agent 1.5 also simplified the API for developers and changed most mentions of "AgentX" (the codename for Microsoft Agent) to "MSAgent" or "AgentSvr". Microsoft Agent 1.5 also installed itself in the Program Files/Program Files (x86) directory. It's character folder was also named "Characters" instead of "CHARS", which is the name of the character folder in Microsoft Agent 2.0.

Microsoft Agent 1.5 is the only official release to have a taskbar icon for the Microsoft Agent Server, which would be removed before the release of Microsoft Agent 2.0 as Microsoft introduced the ability in the Microsoft Agent Character Editor to give characters a custom taskbar icon.

Development

Not much information is known about the development of Microsoft Agent 1.5, since Microsoft Agent 1.5 was added in Windows 98 build 1569 and removed in Windows 98 build 1624. The only four versions known to exist are build, 225, build 232, build 302, and build 416.

Build 225 is the earliest build of Microsoft Agent 1.5 and was compiled on August 18th, 1997. A few builds after this one is build 232, the first RTM release of Microsoft Agent 1.5 that was included in the Microsoft Agent Development Kit to help developers at the time include Microsoft Agent in their software before the download went public. It was also included in Internet Explorer 4 so that developers can already have it used as an ActiveX control on their website.

The next build after 232 is build 302, an unreleased version of Microsoft Agent 1.5 that is confirmed to exist due to the existence of build 302 of the Microsoft Agent Character Editor. The following confirmed build after this one is build 416, which is the latest known build of Microsoft Agent 1.5 that incorporates many bug fixes and also updating the copyright date from 1996-97 to 1996-98.

Exploits

In 2007, exploits were discovered with Microsoft Agent 1.5 characters that allowed for remote code execution. Microsoft quickly fixed this with a patch in Microsoft Agent 2.0 and also warning users whenever a program or website was trying to load a Microsoft Agent 1.5 character on Windows XP. It is believed that this only applied to Microsoft Agent 1.5 build 232, which meant the latest build of Microsoft Agent 1.5 was unaffected by the exploit.

Builds

Build Number	Earliest compilation date	Source	Notes/Issues	Link
Microsoft Agent 1.5.0.225	August 13th, 1997	Windows 98 build 1569	Earliest available build of Microsoft Agent 1.5	225.zip
Microsoft Agent 1.5.0.232	August 20th, 1997	Internet Explorer 4, Microsoft Agent Development Kit, Windows 98 build 1577, Windows 95 OSR 2.5	First public build of Microsoft Agent 1.5	msagent232.exe
Microsoft Agent 1.5.1.302	October 29th, 1997	Unknown	Unknown, build's existence confirmed by Microsoft Agent Character Editor build 302.	N/A
Microsoft Agent 1.5.2.416	February 20th, 1998	VB6 installer & Microsoft website	Bug fixes, updates the copyright year	MSAGENT416.EXE

Gallery

• 
  The property sheet of build 416 with the Microsoft Agent 1.5 taskbar icon below it.
• 
  Internal structure of Microsoft Agent 1.5 ACS file.
• 
  Output tab of Microsoft Agent 1.5.

Trivia

• Microsoft Agent 1.5 came pre-installed on Windows 98 builds 1569 through 1577 before being removed for an unknown reason.
• Despite a popular myth that Microsoft Agent comes bundled with Windows 95, it was found that this was the case for the OSR 2.5 version of Windows 95 as it contains Internet Explorer 4, which bundles Microsoft Agent.
• Not all Microsoft Agent builds are available in Windows betas as it appeared that Microsoft only occasionally updated the Microsoft Agent after each build. This is also why some builds may contain the same version of Microsoft Agent before the version number changes again.
• Unlike the 2.0 installer, the Microsoft Agent 1.5 installer has 2 known versions, therefore meaning the installer was updated at least once.