Question: Google Toolbar is a web browser toolbar for Internet Explorer, developed by Google, it was first released in which year, for Internet Explorer 5 (IE5), is a graphical web browser and one of the main participants of the first browser war?

Context paragraphs:
Internet Explorer 3: Microsoft Internet Explorer 3 (IE3) is an unsupported graphical web browser released on August 13, 1996 by Microsoft for Microsoft Windows and on January 8, 1997 for Apple Mac OS (see IE for Mac).  It began serious competition against Netscape Navigator in the first Browser war.  It was Microsoft's first browser release with a major internal development component.  It was the first more widely used version of Internet Explorer, although it did not surpass Netscape or become the browser with the most market share.  During its tenure, IE market share went from roughly 3–9% in early 1996 to 20–30% by the end of 1997.  In September 1997 it was superseded by Microsoft Internet Explorer 4.

Browser wars: A browser war is competition for dominance in the usage share of web browsers.  The First Browser War was Microsoft's Internet Explorer against Netscape's Navigator during the late 1990s.  Browser wars continued with the decline of Internet Explorer's market share since 2003 and the increasing popularity of browsers including Mozilla Firefox, Google Chrome, Safari, and Opera.

Internet Explorer shell: An Internet Explorer shell is any computer software that uses the Trident rendering engine of the Internet Explorer web browser.  Although the term "Trident shell" is probably more accurate for describing these applications (including Internet Explorer itself), the term "Internet Explorer shell", or "IE shell", is in common parlance.  This means that these software products are not actually full-fledged web browsers in their own right but are simply an alternate interface for Internet Explorer; they share the same limitations of the Trident engine, typically contain the same bugs as IE browsers based on the same version of Trident, and any security vulnerabilities found in IE will generally apply to these browsers as well.  Strictly speaking, programs that use Tasman (layout engine), used in Internet Explorer 5 for Apple Mac, are also IE shells, but, because Internet Explorer for Mac was discontinued in 2003, and Tasman was further developed independent of IE, it tends to be thought of as a separate layout engine.

Browser extension: A browser extension is a plug-in that extends the functionality of a web browser.  Some extensions are authored using web technologies such as HTML, JavaScript, and CSS.  Others are developed using machine code and application programming interfaces (APIs) provided by web browsers, such as NPAPI and PPAPI.  Browser extensions can change the user interface of the web browser without directly affecting viewable content of a web page; for example, by adding a browser toolbar.

Internet Explorer 7: Windows Internet Explorer 7 (IE7, codename "Rincon") is a web browser for Windows.  It was released by Microsoft in October 2006.  Internet Explorer 7 is part of a long line of versions of Internet Explorer and was the first major update to the browser in more than 5 years.  It is the default browser in Windows Vista and Windows Server 2008 and can replace Internet Explorer 6 on Windows XP and Windows Server 2003 but unlike version 6, this version does not support Windows NT 4.0, Windows 98, Windows 98 SE, Windows 2000, and Windows ME.

Google Toolbar: Google Toolbar is a web browser toolbar for Internet Explorer, developed by Google.  It was first released in 2000 for Internet Explorer 5.  Google Toolbar was also supported on Firefox from September 2005 to June 2011.

Internet Explorer 5: Microsoft Internet Explorer 5 (IE5) is a graphical web browser and one of the main participants of the first browser war.  Its distribution methods and Windows integration were involved in the "United States v. Microsoft Corp." case.  It is included with Windows 98 SE and Windows ME and it is the last version of Internet Explorer for Windows 3.1x, Windows NT 3.x and Windows 95.  Although Internet Explorer 5 ran only on Windows, its siblings Internet Explorer for Mac 5 and Internet Explorer for UNIX 5 supported Mac OS X, Solaris and HP-UX.

Internet Explorer 11: Internet Explorer 11 (IE11) is the last version of the Internet Explorer web browser by Microsoft.  It was officially released on 17 October 2013 for Windows 8.1 and on 7 November 2013 for Windows 7.  The browser was also shipped with Windows 10 on its release on 29 July 2015, but Microsoft Edge is the default browser in this version of Windows.  It is the default browser shipped with Windows Server 2016.  After 12 January 2016, only the most recent version of Internet Explorer to be offered for installation on any given Windows operating system will continue to be supported with security updates, lasting until the end of the support lifecycle for that Windows operating system.  On Windows 7, 8.1, and 10, only Internet Explorer 11 will receive security updates for the remainder of those Windows versions' support lifecycles.

Browser toolbar: A browser toolbar is a toolbar that resides within a browser's window.  All major web browsers provide support to browser toolbar development as a way to extend the browser's GUI and functionality.  Browser toolbars are considered to be a particular kind of browser extensions that present a toolbar.  Browser toolbars are specific to each browser, which means that a toolbar working on a browser does not work on another one.  All browser toolbars must be installed in the corresponding browser before they can be used, and require updates when new versions are released.

Windows Live Toolbar: Windows Live Toolbar was a browser extension toolbar for Internet Explorer.  It superseded MSN Search Toolbar.  Windows Live Toolbar provided a simple search interface that starts to list results as the user types in a search query, and uses Bing as its search engine.  The toolbar also allows users to synchronize their Internet Explorer favorites across multiple computers, and provides an interface to Windows Live and MSN services.

Supporting paragraphs: Google Toolbar Internet Explorer 5
Answer: 2000