1)   Help Explorer Viewer for Linux 3.0
Help Explorer Viewer is a full-featured help viewer for both Windows and Linux. One of its main advantages is 100% support of the WinHelp (.hlp), MS HTML Help 1.x (.chm) and MS Help 2.0 (.HxS) help file formats that are widely used in Windows.

 2)   Help Explorer Viewer for Windows 3.0
Help Explorer Viewer is a full-featured help viewer for both Windows and Linux. One of its main advantages is 100% support of the WinHelp (.hlp), MS HTML Help 1.x (.chm) and MS Help 2.0 (.HxS) help file formats that are widely used in Windows.

 3)   Help Explorer Server 1.0
Help Explorer Server is a web-based application designed for viewing compiled help files in different formats: Microsoft Windows Help (WinHelp) - .HLP, Microsoft HTML Help 1.x - .CHM, and Microsoft Help 2.0 - .HXS.