Which tool to use to develop toolbar for Internet Explorer and Firefox?

I want to develop toolbar for Internet Explorer and Firefox. Is there any common tool? If not, which tool 开发者_开发知识库can be used?

Thanks for reading.

Regards, Sanket

Firefox: Firebug, Web Developer

IE: Developer Toolbar, Fiddler and this crazy new one: dynaTrace

You can use Visual Studio to develop a toolbar for IE. This site gives a detailed walkthrough of the process.

(I believe your question is how to develop a toolbar, not what developer toolbars are available but please correct me if I'm wrong.)