Mozilla is a global, nonprofit organization dedicated to improving the World Wide Web. Mozilla’s international community of developers creates open source software such as Firefox, which is the second most popular web browser with about 16% of worldwide usage.

Currently, Firefox is undergoing the largest redesign in its history. This redesign involves new styling, new features and new ways for Firefox to do multiple tasks simultaneously.

Options in Firefox are often presented to users in the form of a list like the one at the right, which is called a “select dropdown.” Our improvements to the select dropdown implement the new Firefox styling and add new search features. Our improvements provide a more modern and faster web browsing experience.

With our new search functionality, users can find items in a long dropdown list quickly by typing a few letters from the item of interest, like the example of typing “Mi” shown at the right. Only the list items that contain these search letters appear in the list, thereby shortening the list and making it much easier to find the desired item.

Our improved select dropdown also features enhanced styling with modern web fonts used by the computer on which Firefox is running, which gives a more seamless and familiar browsing experience to roughly half a billion Firefox users worldwide.

Our improvements to the select dropdown require the addition of code in many sections of Firefox’s 4.5 million line code base. Our code is written in C++, JavaScript and XUL. The new styling is accomplished with CSS.