• Free Software Foundation (www.fsf.org)- Supports the GNU project, which produces much of the software outside the kernel that is associated with Linux. In particular, open source versions of nearly every early UNIX command have been implemented by the GNU project.
• Apache Software Foundation (www.apache.org)- Produces the Apache(HTTP) Web serwer. It also manager related projects, such as spamAssassin content (perl, SSL, PHP, and so on).
• K Desktop Environment (www.kde.org)- Develops KDE, one of the two leading desktop environments used with Linux.
• GNOME (www.gnome.org)- Develops the other leading Linux desktop environment (used as the default desktop for Red Hat Linux systems).
• X.org (www.x.org) and XFree86(www.xfree86.org)- These two organizations provide different implementations of the X windows system graphical desktop framework software.
• Internet Systems Consortium (www.isc.org)- Develops several major open source software projects related to the Internet. These include Bind (domain name system server), INN (InterNetNews news serwer), and DHCP(dynamic host configuration protocol).