Firefox utilizes the Mozilla code repository called Mozilla Code Studio for producing portable applications, and for building Portable Security Applications (PSA) - a web browser security application that can be used for detecting security vulnerabilities. Firefox also utilizes the Open Source code repository called Mozilla repository for the source code. Mozilla has licensed the source code so that other companies or people cannot use it for any purpose without permission. The Mozilla developers also continue to optimize the coding to make it run faster and more efficiently on different operating systems including Windows, Linux, Mac OS, and Solaris.
Mozilla Firefox has a number of new features that make browsing the net a more enjoyable experience, including the Windows interface, the Firefox toolbar, and the built-in search engine. The Firefox designers took advantage of the Microsoft public license for this. They made this open source web browser available under the Mozilla Public License (MPL), which allows free downloading and usage on the internet. This means that anyone who downloads the Mozilla Firefox 3 will not have to pay royalties for the software.