IE add-on/extension/bho/plugin creation

I'm trying to build a simple extension for IE which performs several simple tasks e.g. highlight text, clear highlighting. My first problem is that MS seems to have many related technologies which leads to confusion. I'm not sure whether I'd be building a browser helper object, an activity, a tool band, an explorer bar, a web accessory, an add-on, or some com开发者_运维百科bination of the above.

It looks like you can create context menu items via the creation of registry entries, but as far as I can tell I can only perform a single task in a COM object or script. Is that true? Do I need a separate COM object or script file for every single feature or menu item I create? Is there a better approach which would allow me to create a single COM dll and have multiple menu items call separate methods?

Also, the references I've seen suggest writing a COM object in C++, which is really suboptimal in terms of ease of coding. I'd be manipulating the DOM of the current web page, and that's certainly easier in a higher-level language than C++.