1.Fiddler2  

 More Info: http://www.fiddler2.com/fiddler2/
> Addons for Fiddler2 - http://www.fiddler2.com/Fiddler2/extensions.asp
> Documentation for Fiddler2 - http://www.fiddler2.com/Fiddler/help/
>

2.GreaseMonkey for IE

http://www.gm4ie.com/

3.Tamper IE: http://www.bayden.com/TamperIE/ ......... (similar to
Tamper Data on Firefox)
Internet Explorer Developer Toolbar ....... (Similar to Web developer
toolbar for Firefox)
HTTP Watch: http://www.httpwatch.com/
Watir: http://wtr.rubyforge.org/  ........ (Browser automation)
IECookiesView: http://www.nirsoft.net/        ......... I think this
will solve the cookie manipulation.