AxScripter is an essential tool for every developer who uses ActiveX-enabled scripting language, including VBScript and JavaScript (JScript). It can be connected to any scripting host (for example,  Internet Explorer and Windows script host) and provide you with a full featured debugging environment for testing and correcting errors in your Web document scripts.

Features:

    #  Conditional break-points- customize your breakpoints so if your program pauses only when a specified set of conditions is met. AxScripter ensures 2 types of breakpoint conditions: Boolean expressions and Pass count.
    #  Tooltip expression evaluation-When you are debugging and you are stopped, you can place the mouse cursor over any variable or property name in the code editor to display its value at that time.
    #   Powerful code editor-editing and viewing source code with powerful syntax highlighting, text folding, text structure tree view, Stack-based markers , Unlimited bookmarks and Multiple Sync Edit regions.
    #  Key mapping scheme - The following key mapping modules are available, Visual Studio.NET ,Eclipse and Delphi. To change key assignments for editor commands you can use "Key mapping" customize dialog.
    #  Customizable desktop settings-Arrange the desktop as you want it including displaying, sizing, and docking particular windows, and placing them where you want on the display. You can save your desktop settings and create as many layouts as you like.

Link to the official website: http://www.ieinspector.com/scriptdebugger/