How should a web developer approach building a Browser toolbar?

I am a web developer looking to build a browser extension. What is开发者_StackOverflow社区 the best way to build browser extensions using web technologies (HTML, Javsacript, etc). We are targeting IE and Firefox only. Can IE browser toolbars be created using HTML/Javascript?

There is a bit of confusion here. Your question title says you are looking to develop a "Browser Toolbar", but in the question body itself you are asking about "Browser Extensions".

Its important to understand that in general Browser Toolbars are a subset of a Browser Extension. If you are indeed looking though to develop a Cross Browser Extension and not a toolbar I would really recommend the use of Crossrider - a development framework for cross-browser extensions.

They do not allow you develop toolbars, but they do have an online IDE and an extensive API to build cross-browser extensions for Internet Explorer, Chrome, Firefox and Safari with basic knowledge of JavaScript and jQuery.

Have a look at this article where they discuss using HTML and Javascript to build an extension for firefox.