There are instances when you need customized browser. There are circumstances where your browser looks disabled for so many other things that you want to do. BHO stands for Browser helper object and is a straight forward way to customize your Internet Explorer.  BHO enables you to add additional functionality to your browser like adding toolbars, add-ons, sidebars, deskbands, and so much more. To enable browser helper object, developers have to write two types of codes: for the full-fledged development of the browser so that it can accomplish the entire task that it is meant for. And the other type of code enables it to add the features that the browser doesn’t contain. BHO developer integrates code in your existing browser so that it builds the capacity to absorb the additional features and extend itself to satisfy user’s demand.

Lifecycle of Browser Helper Object

BHOs aren’t just supported by Internet Explorer; your BHOs will also be loaded by Windows Explorer—meaning that a unique browser can navigate both the Web and local disks with a similar user experience. A browser helper object has a short lifecycle. It is loaded with the application window which is about to be displayed and kills itself once the window is destroyed. In general, the BHO is launched when either explorer.exe or iexplore.exe executes.

Which technology is best suited for BHO development?

Active Template Library (ATL) is considered the best for BHO developer. ATL already provides a default and good enough implementation of the IObjectWithSite interface.