Linux
Linux is a free, Unix-type operating system originally created by Linus Torvalds with the assistance of developers around the world. Developed under the GNU General Public License, the source code for Linux is freely available to everyone.
Two cool starter sites for Linux:
www.Linux.org and
www.Linux.com.
MySQL
MySQL is the world's most popular Open Source Database, designed for speed, power and precision in mission critical, heavy load use.
PostgreSQL
PostgreSQL is a sophisticated Object-Relational DBMS, supporting almost all SQL constructs, including subselects, transactions, and user-defined types and functions.
Apache
The Apache Software Foundation provides support for the Apache community of open-source software projects [most notably, the Apache web server]. The Apache projects are characterized by a collaborative, consensus based development process, an open and pragmatic software license, and a desire to create high quality software that leads the way in its field.
PHP
PHP is a widely-used general-purpose scripting language that is especially suited for Web development. PHP with MySQL on Linux is becoming a defacto web-based application standard.
PERL
Perl is traditionally the most popular web programming language due to its facility
with text manipulation and rapid development cycle. Although it has been called "the
duct-tape of the internet," PERL predates the proliferation of the world wide web and
offers much more functionality, combining the best features from other languages, such as C, awk, sed, sh. O'Reilly maintains a nice PERL site too: www.perl.com
The Gimp
The GNU Image Manipulation Program (GIMP) is a feature-rich, freely distributed piece of software designed for such tasks as photo retouching, image composition and image authoring.
It can be used as a simple paint program, an expert quality photo retouching program, an online batch processing system, a mass production image renderer, an image format converter, etc.