For the GNU perspective on many of the issues mentioned here refer to http://www.gnu.org/philosophy/free-software-for-freedom.html. This article, titled Why ``Free Software'' is better than ``Open Source'' is written by Richard Stallman and is an essential read on the topic. It explains why the use of the term ``Open Source'' is not strong enough in the context of ``Free Software.''
Freshmeat (http://freshmeat.net/) is an index of a large collection of GNU/Linux packages with up-to-date information on their status and links to their home pages and related locations. The index can be searched or browsed. Most of the GNU/Linux tools are included.
Gnome (http://gnome.org/) is the framework and associated toolkit used by many of the graphical applications introduced in this book. The Gnome web site includes a list of many of the major Gnome applications.
Linux Today (http://linuxtoday.org/) is a news service providing updates on developments related to GNU/Linux. It has a good selection of articles usually updated several times a day, and does not overwhelm the reader with news. Summaries are presented with links to slightly more detailed summaries, with links to the complete articles, wherever they appear on the Internet. Slashdot (http://slashdot.org/) is another news service with a Linux bent.