This section is dedicated to Linux. You will find lots of information, guides, how to's, tips etc in this page.
Just incase you don't know, i use Gentoo Linux.

This is the online home of Version Control with Subversion, a free book about Subversion, a new version control system designed to supplant CVS.
Version Control with Subversion

Windows version:
http://passwordsafe.sourceforge.net/

Linux:
http://www.semanticgap.com/myps/

They are both compatible with each other.

howto configure Xorg to use the correct fonts and make it look great:
Gentoo Forum

* app-text/docbook-sgml-utils
Latest version available: 0.6.12
Latest version installed: [ Not Installed ]
Size of downloaded files: 115 kB
Homepage: http://sources.redhat.com/docbook-tools/
Description: Shell scripts to manage DocBook documents

http://www.sciencemag.org/feature/contribinfo/prep/TeX_help/index.shtml

Howto:
http://nis-www.lanl.gov/~rosalia/mydocs/docbook-intro.html

Apache2 Documentation:
http://httpd.apache.org/docs-2.0/

A Bare-Bones Guide to Firewalls:
http://linuxgazette.net//103/murray.html

Firewalling with netfilter/iptables:
http://linuxgazette.net//103/odonovan.html

Some howto's here:
http://www.linuxkungfu.org/

Gentoo:
http://forums.gentoo.org/viewtopic.php?t=159133&highlight=iptables
http://forums.gentoo.org/viewtopic.php?t=159710&highlight=iptables
http://www.gentoo.org/doc/en/gentoo-security.xml#doc_chap13

Oskar Pearson's tutorial:
http://iptables-tutorial.frozentux.net/

Iptables firewall generator:
http://linux.tkdack.com/module.php?mod=firewall

Arch

Long tutorial

Article:
An article about it

90% of what you need is in "The Not So Short Introduction To Latex". If you have latex
installed, it's probably on your HD already:

file:/usr/share/texmf/doc/newhelpindex.html

file:/usr/share/texmf/doc/latex/latex2e-html/ltx-2.html

Then there's CTAN and TUG:
TUG
http://www.tug.org/tex-archive/help/Catalogue/bytopic.html

For math related stuff

For making nice graphs, check out JFreeChart. It's easy to use and makes nice graphs,
but you need to know some basic Java programming to use it.

Gentoo Forum Link

Inkscape is an open source SVG editor with capabilities similar to Illustrator,
CorelDraw, Visio, etc. Supported SVG features include basic shapes, paths, text, alpha
blending, transforms, gradients, node editing, svg-to-png export, grouping, and more.
inkscape
Open Clipart

Linux support for Easy Access and Internet keyboards (e.g. Compaq). Features: X11 support : Window Manager independant : all keys user-configurable (GUI & .conf file) : volume control : sound controls.
LINEAK

This website has everything about Assembly.
Even High Level Assembly, which is a very interesting language
Art of Assembly

This is a great tutorial to get you started with using MySQL with PHP.
This is what i used to learn, its a great beginner.
PHP/MySQL Tutorial

These are two great howto's to get you going with Prolog.
Learn Prolog
Prolog Course

This simple web application, written in PHP with a MySQL backend, provides a scalable way of presenting and organising projects that you or your company work on.
2do - Todo-List

This website has some great guides to get you started with CGI.
Learn CGI

Coda is a distributed filesystem with its origin in AFS2. It has many features that are
very desirable for network filesystems. Currently, Coda has several features not found
elsewhere.

1. disconnected operation for mobile computing
2. is freely available under a liberal license
3. high performance through client side persistent caching
4. server replication
5. security model for authentication, encryption and access control
6. continued operation during partial network failures in server network
7. network bandwith adaptation
8. good scalability
9. well defined semantics of sharing, even in the presence of network failures
Coda File System

This is a fantastic Exchange server, It can use existing email server and it works with all major clients, such as Outlook, Evolution and Mozilla.
I hopw to implement this on my server in the future. Its a great project, should keep an eye on its progress.
http://www.opengroupware.org

Great howto for getting people started with Vim. It says its for Perl developers, but it applys to everyone.
Vim for Perl developers

I found 2 great howto's to get your SSL, in your webserver, working. They teach you howto create your SSL certificates.
OpenSSL Certificate Cookbook
SSL and secure servers

This is a nice howto on OpenLDAP. It will get you started with LDAP, learning the basics. It will show you how to build an addressbook.
OpenLDAP Howto

This is a nice backup solution if you want to keep all your work backed up. It can do cumulative backup, so that you save time and bandwidth. It keeps a record of all the changes, just like CVS or Subversion. I use it to keep all my work safe.
rdiff-backup

Great howto: Email System For The Home Network.
I recommend anyone who wants to setup an email server in there home to read this guide. It is very detailed and helps you to setup email server through your ISP's server.