― Developing browser extensions can be a daunting task. If you want to release a version of your extension for each major browser in the market, you basically have to develop a different extension for each one of them. Sometimes you'll be able to reuse code (e.g., between Chrome and Safari extensions), and sometimes not (e.g., between Firefox and IE extensions). ∙ Let's present three different ways of developing an extension for different browsers. Each way basically represents a different [...].