How to create common browser add-on/extension?

Question

Most browsers allow extensions for them. But, as I understand, there separate extensions needed for different browsers.

Is there any way to write one extension for all browsers? Can such thing be created Java, .NET, or Python?

Answer 1

In my opinion you can use Crossrider, with Crossrider you will write one JavaScript code, that will produce an Chrome,Firefox and Internet Explorer compatible extension.
Crossrider have a powerful API that hide all complexity while writing cross-browser code.

Try to give it a shot in: http://www.crossrider.com

Disclaimer: I worked at Crossrider

Answer 2

It depends what your extension does. Theoretically if your extension is quite simple (e.g. it doesn't require any special APIs like http, or filesystem access and it doesn't modify browser layout), than theoretically you can reuse the same code between browsers (but since each browser has its own extension format, you must create descriptors/browser specific code for each extension). Writing extensions in language other than javascript is possible by using some Name our language to JS compiler. For example SpeedTracer for Chrome is partially written in GWT (Java to JavaScript compiler).

So in short, you can reuse the same code between extensions for different browsers and you can use languages other than javascript to create browser extensions.