It shipped with Linux 2.6.11, KDE 3.4 and GNOME 2.10. These packages included KDE, X Window System, OpenOffice, GNOME, and Mozilla. Fedora Core 3 shipped with GNOME 2.8 and KDE 3.3. MacOS, and has graphical user interface clients for Windows, GNOME, and KDE. Separate GNOME and KDE versions are available. Support for this is present in KDE, GNOME and other desktop environments. GNOME Shell is the default graphical shell of the GNOME desktop environment. GNOME 3.22 included much improved Wayland support across GTK, Mutter, and GNOME Shell. This means Compiz cannot be used in conjunction with GNOME Shell. Budgie applications generally use GTK and header bars similar to GNOME applications. GNOME Keyring is part of the GNOME desktop. Mozilla Thunderbird has replaced the GNOME Evolution email client. Red Hat is the largest contributor to the GNOME desktop environment. It was designed for the GNOME desktop environment. Users can find and install extensions using the GNOME extensions website.