Mozilla is an open source project that is currently developing the popular <ahref="https://www.mozilla.org/firefox">Firefox</a> internet browser, the email client <ahref="https://www.mozilla.org/thunderbird">Thunderbird</a> and the application suite SeaMonkey. Mozilla chose Mercurial in 2006.</p>
OpenJDK is the official open sourced Java implementation of Sun Microsystems. When open sourcing the project, Sun chose Mercurial as their main version control system.