Microsoft Help Viewer
Microsoft Help Viewer (HV) is the offline help system (local help) developed by Microsoft that ships with versions of Microsoft Windows including and subsequent to Windows 8, as well as Visual Studio 2010 and its associated MSDN Library. Microsoft Help Viewer 1.x supersedes Microsoft Help 2 which is the help system used by Microsoft Visual Studio 2002/2003/2005/2008 and Office 2007. It is shipped with VS 2010. Microsoft Help Viewer 2.x is backwards-compatible with 1.x and is shipped with the operating system as well as VS 2012+. Although Microsoft Help Viewer was referred to as MS  Help 3.x during development, it is a wholly new product and technically unrelated to Microsoft Help 2. With the growing need for a general Unicode-based help system, has become the default help system for Windows 10. History. The HelpPane Viewer is found in Windows 10. The version appears to be 2.3. User Experience. The user experience for Microsoft Help Viewer 1.x is that topics can be viewed in any installed web browser – a separate application, such as the Microsoft Document Explorer included with Microsoft Help 2, is not necessary. The browser-based model is meant to provide a more  lightweight navigation, downloading, and reading experience than earlier help-viewer models. Visual Studio 2010 includes a taskbar applet in the Windows notification area (system tray) that arbitrates between viewing offline help and online help in the browser when F1 is pressed, and resolves help topic URIs to the proper topic page. It also includes a "library manager" application to manage the download, installation and uninstallation of help topics on the system, as well as whether to prefer online help when connected to the Internet. Microsoft Help Viewer 2.0 uses a COM runtime library, so the taskbar applet is no longer  used. The format is unchanged. The runtime API is accessible via .NET dlls used in VS2012 and Windows 8; they are equivalent except for a name change. VS2012 ships a more sophiscated toolkit (HlpViewer and HlpCtntMgr), while Windows 8 only has a one-pane HelpPane program. File format. Help files from Microsoft Help Viewer have a file extension. They are ordinary Zip files containing HTML documents. Special meta tags are provided for navigation, and there is support for signing the help bundle.