Web servers are optimized to serve potentially millions of pages while tracking minimal amount of user state data;
Application servers are optimized to host single applications to few hundred to a thousand users, while tracking massive amounts of data of user state. 
A lot of sites use a combination of the two to provide services, take yahoo.com for instance, the home page is served by a bank of Web servers, once you click on one of the services such as games or Instant Messaging you are now interfaced to an Application server.

For all those beating up Opensource software, the largest and fastest web database deployment is currently google's which on the backend runs MySQL  http://www.mysql.com/customers.  Also Yahoo's finance and email are embedded MySQL applications.

Apache another opensource application is the most dependable and deployed Web server on the internet.

PHP is the fastest growing web development language and boasts the most active online support sites.

The lesson is this, if you stand to lose thousands of Dollars per minute in development time go with the Commercial applications, but if you have 2 to 20 months to develop an application, you can develop robust systems with OpenSource packages.  A trip to http://sourceforge.net  will reveal a host of Enterprise, Award winning software from the OpenSource communities.

Gone are the days when OpenSource was synonymous with "unstable, buggy, and undependable" software.   Dependable enough that the European union(EU) has an ongoing programme of migrating to a 100% OpenSource architecture http://ec.europa.eu/idabc/en/document/2623 .

My hope is that someday African nations will support their software development industry so that applications can be localized to serve the populace which OpenSource is geared to do

Note: changed the link to the EU page as it had changed

In New York, where I live, one does not need to attend any institution to sit for a certification tests. All one needs is confidence in the subject, testing fees and an appointment at the testing facility ( mos likely http://www.prometric.com/default.htm). I have held several certifications over my 9 years, and have never "had" to go to an institution to learn.

I simply go to the site of the software developer, download the free version of their software along with the manuals. Find a couple of my servers and reinstall to match the software requirements. I Read the manuals while playing with the software, until I know enough to pass any test that may be given in regards to the software in question.

I book a testing date, take along my pencils and ID and go sit for the exam. Using the methodology, the only Exam I ever failed was part 2 of my Sun Solaris exam in 1999. I failed cause I was so confident, since I worked on solaris servers everyday, I never read the manuals nor visited Sun's educational site to see what was going to be tested. Later in the exams I discovered questions about printing and setting up dialup modems, Since I used Sun servers only for Firewall and SecurId systems, I never came across these uses for Solaris.

OK, I hear that one may need a guide, but what better guides than the developer's educational unit which are accessible from the Oracle University online forums?

And here I am thinking the Oracles Certificates were all issued by "Oracle" certified outlets, making any certificate from anywhere in the world equal.

Viper is absolutely right in the theoretically strictest form of MVC, I just wish I can be disciplined enough not to cheat by inserting DB queries into my "views", and generating outputs from my "controllers" because I dont want to spend the 30 minutes to amend a header file.

Oh my lordy lordy !
I damn near rolled of my chair.
That is funny as hell(no pun intended) .

I used a relatively light weight framework called Codeigniter from http://codeigniter.com/ to develop oroede at http://oroede.sourceforge.net/oroede/. Using the framework saves time, being like you mentioned it is a pain to reinvent the wheel everytime you have to develop an application.

Each framework has it pros and cons. I chose CodeIgniter because it was easy to learn, as seen from their introductory tutorial at http://codeigniter.com/tutorials/ , but CakePHP has been a headache to learn, but it has been around longer and has a bigger code-base with really cool integration to Web 2.0 technologies such as AJAX, where CodeIgniter is just catching up.

Zend's framework is supported by the writer's of the Engine of PHP, but it is still in "Beta" development stage and woe to one who spends month developing on "Beta" platform only to find that final release breaks all your code. In the long run once stable, Zend will be the framework for me, cause those guys at Zend do great work.

I hate to cross post as I gave this already at https://www.nairaland.com/nigeria/topic-28642.64.html#msg881289
but here are links you need for oracle software and documentations towards certification

You can download the personal edition of Oracle 10G(DB clustering and some form of application embedding is disabled)
http://www.oracle.com/technology/software/products/database/xe/index.html

For Oracle 10G certifications you can download all the guides and manuals here
http://www.oracle.com/please/db102/homepage


You get tutorials and tons of examples and tips here
http://www.oracle.com/technology/training/index.html

If you sign up for a free account at Oracle University you get even more articles from the experts at
http://education.oracle.com/web_prod-plq-dad/plsql/show_desc.redirect?redir_type=3&p_org_id=&lang=&source_call=global


All in all you get everything you need to pass each step in your certification plus an online support community, and all for free, and all thanks to the good folks at Oracle.

For those who are interested in becoming Oracle certified, you don't have to pay for anything if you have full access to at least 2 computers that are interlinked and you can monopolize during you learning. Here I will give you the links to Oracle supplied softwares, documentations and tutorial from the Oracle University.

You can download the personal edition of Oracle 10G(DB clustering and some form of application embedding is disabled)
http://www.oracle.com/technology/software/products/database/xe/index.html

For Oracle 10G certifications you can download all the guides and manuals here
http://www.oracle.com/please/db102/homepage


You get tutorials and tons of examples and tips here
http://www.oracle.com/technology/training/index.html

If you sign up for a free account at Oracle University you get even more articles from the experts at
http://education.oracle.com/web_prod-plq-dad/plsql/show_desc.redirect?redir_type=3&p_org_id=&lang=&source_call=global


All in all you get everything you need to pass each step in your certification plus an online support community, and all for free, and all thanks to the good folks at Oracle.

The most stable OpenSource teaching Content Management System(CMS) is Moodle at http://moodle.org/ it is easy to use once properly installed. It has tons of add on modules to satisfy the diverse operational requirements of a school system.

As a CMS it frees the author/user to create and publish their content without worrying about coding and it has huge online community support including non-profits, schools, governments and creative programmer's.

if you are a non-profit school I will assist you in the setup and installation, else you can get one of the developers here to assist you or go to the software support site where you can get general help

Okay I have a bunch of snippets I usually use, but here are sites that have some of the best Code Snippets

PHP:
http://www.zend.com/code/codex.php
http://www.phpbuilder.com/snippet/
http://www.php-csl.com/snippets/
I stop here cause a thorough search of google.com can get you real cool snippets sites.
MySQL:
http://forge.mysql.com/snippets/

Honorable mentions to
http://www.phpfreaks.com (I started my PHP learning from the articles and references here)
http://www.phpclasses.org/ (not really snippets but this has the largest repository of OpenSource PHP classes for Object Oriented Programmers. you know what they say about "classes"? The more class file you have, the more more time you have to spend at the beach. Save time, use classes!!!)


General (these have code snippets from several technologies):
http://snippets.dzone.com
http://www.snippetlibrary.com/code.php

My story is not too different from Andre5, only I got to work with enterprise companies in the early 1990 as a security consultant(which meant you had to help the in-house coders find errors in their TCP stack sequences to prove that it was not the fault of the firewalls that their web streams were failing). That is when I fell in love with programming, since what I did in the labs at University of Abuja could ever be called programming, more like knocking code together and seeing if I could get the lab assistant to pull some hair out.

I have since had to learn several compiled and interpreted languages, applications, protocols, suites, databases and "What_have_yous" and I know I will have to learn even more as the new "it" comes along. I get excited about "it", pore through "it's" manuals, create a development environment to match "it's" requirement, get "it" to work, modify "it", and then go to "it's" support forum to assist those who have not solved "it".

Recently though I notice I am less inclined to reformat a server in order to get a new software to work, or at my Job where we host a lot of cutting edge websites using bleeding edge technologies, lots of which are OpenSource such as the red5 flash server at osflash.org/red5 or some other new fangled commercial application with unstable integration to service structures such as Apache or Sendmail, I am inclined to do "more research" than just "jumping in" to it.

I still get a lot of kicks out of new technologies, but I do pour libations to the volumes of manuals I have perused, whose applications I will only remember someday when I visit the halls of The SmithSonian, that will be devoted to "Forgotten versions of Operating Systems, applications, protocols, databases, utilities and software suites"

To be hot in either of those fileds, one and only one jumps to mind, "Flash + Actionscript" from Adobe. Like the name says, it is all about the pazazz, small foot print, great imagery and effects, robust framework. Did I mention the PAZAZZ?

I love "Flash" and now that Adobe has consolidated and better integrated it with their Dreamweaver, Photoshop and other creative applications in CS3 http://www.adobe.com/products/flash/?ref=odevtr.info, it is hands down the entertainment and telecommunication development platform for user interactivity.

Downside to all these is of course the price for a license at $699 from http://www.adobe.com/products/flash/. if you can secure a copy of an older version which are much reduced on some development online community sites.

What programming language are you interested in?

You can get tons of tutorials at http://www.tutorialized.com/ . This site has tons of tutorials for Flash, Photoshop, CSS, and all major Contemporary web development languages.

If you are not sure, and the only environment you have used is Windows, consider downloading a free copy of Microsoft Visual Studio Express from http://msdn.microsoft.com/vstudio/express/. Microsoft provides a lot of tutorials you can follow and learn from.

If you want a language unencumbered by licensing with more flexibility and a large community of online supporters ( please all you ASP developers don't flame me, just my opinion) you may learn PHP.

At Oroede Development Group we have lots of video tutorials, but they can only be made available to development volunteers. Visit us at http://oroede.sourceforge.net/ volunteer, and you will learn a lot while helping a good cause.

If you are in early development stages in your application, you may be better off using a "Development Framework", which already have fully developed user management modules and tons of other useful modules. I personally used http://codeigniter.com which has a very light code weight and is easy to get started with watch these introductory video http://codeigniter.com/tutorials/.

However if you are doing major application development with a team behind you, you may chose one of the more optimized frameworks such as http://www.cakephp.org/ or http://www.symfony-project.com/.

If all you simply want is a prepackaged set of authentication scripts, you will find them here http://www.hotscripts.com/search/14908215.html Simply follow and modify the code to suite your application to your heart's content.

Lest I forget my favorite resource, http://sourceforge.net/ you will find tons of full fledged PHP OpenSource applications with scripted authentication systems, whose code you may peruse to learn tested OOP based secure auth variable/logic layouts, including all important concepts such as "filtering input and escaping output" of variables.

Yes you may run both on the same machine, but you will have to run the processes off different ports. On one of my development servers I run Apache on ports 8000 - 9000 and all IIS virtual sites on port 80