Internet Explorer extensibility

http://en.wikipedia.org/wiki/Internet_Explorer#Extensibility

Internet Explorer Architecture

Internet Explorer Browser Extensions

Adding Toolbar Buttons

Adding Menu Items

Class for Adding Buttons, Menu Items and Explorer Bars to Internet Explorer

SpicIE - Simple Plug-In Creator for Internet Explorer
SpicIEContrib - SpicIE plug-in samples & guidance

Sample showing how to handle refresh and drop down buttons in IE



http://en.wikipedia.org/wiki/Browser_Helper_Object

http://msmvps.com/blogs/vcsjones/archive/2010/05/23/writing-a-managed-internet-explorer-extension-part-1.aspx

http://www.codeproject.com/KB/cs/Attach_BHO_with_C_.aspx

http://www.xtremevbtalk.com/showthread.php?t=53876