Using Firefox/Developers
Extension Development
editThe most comprehensive site for Extension development is at the Mozillazine Knowledge Base found here. Other helpful tools include the DOM Inspector included in Firefox and the JavaScript console.
Firefox is especially developer-friendly. It allows even the most casual web developer to crib useful HTML techniques from most any website they visit, and offers a host of other features for more serious users.
Source viewing
editPerhaps the most-used development feature is the ability to highlight images and text in any website, and choose to view source from a drop-down menu. When this feature is used, Firefox displays the HTML source that was used to generate the highlighted content.
For instance, highlighting the above paragraph and section heading, right clicking, and choosing "View Selection Source", will display the following in a new window:
<p><a name="Source_viewing" id="Source_viewing"></a></p> <h2>Source viewing</h2> <p>Perhaps the most-used development feature is the ability to highlight images and text in any website, and choose "<i>View selection source</i>" from the drop-down menu. Doing this will bring up a pop-up window, with the HTML source that was used to generate the highlighted content.</p>
Combining this technique with a good markup language reference source, such as the Wikibook HTML Programming, will allow you to learn from every new website you visit.