Read more @ Wikipedia, the free encyclopedia.

Additional links

http://www.sacredcowdung.com/archives/2006/03/all_things_web.html

http://www.readwriteweb.com/archives/web_20_backpack_web_apps_for_students.php

http://www.smashingmagazine.com/2007/03/10/web-20-tutorials-round-up/

Konqueror

1. Click on the Settings-menu in Konqueror
2. Click on the Configure Konqueror… item in the menu – a new window opens
3. Click on Cookies on the left side (you might have to scroll first)
4. Set Accept all cookies by default.
5. Save changes by clicking Ok.

Lynx

1. Press O for Options
2. Look for General Preferences and Cookies (!)
3. Set it to either ask user or accept all (more convenient)
4. Save changes by selecting Accept Change

Mac IE 5.x

1. Click Edit
2. Select Preferences
3. Under the Receiving Files option, select Cookies
4. Under “When receiving cookies:” select the desired level of cookie acceptance
5. Under “When receiving cookies:” select the desired level of cookie acceptance
6. Click OK to finish

Mac IE 4.x

1. Go to My AOL on the menu bar
2. Pick WWW
3. Go to the Advanced Settings option on the Category menu
4. Click “Cookies”
5. When receiving cookies: Click “Never Ask”
6. Click OK

Internet Explorer 7

1. Open your browser, and select Internet Options from the Tools menu at the top.
2. Now on the option screen select the Privacy tab.
3. Make sure the slider is not set to “Block All Cookies”.

Microsoft Internet Explorer 6.0

1. Select “Internet Options” from the Tools menu.
2. Click on the “Privacy” tab.
3. Click the “Default” button (or manually slide the bar down to “Medium”) under “Settings”.
4. Click “OK”.

Microsoft Internet Explorer 5.x

1. Select “Internet Options” from the Tools menu.
2. Click on the “Security” tab.
3. Click the “Custom Level” button.
4. Scroll down to the “Cookies” section.
5. To enable:
   1. Set “Allow cookies that are stored on your computer” to “Enable”.
   2. Set “Allow per-session cookies” to “Enable”.
6. Click “OK”.

Microsoft Internet Explorer 4.x

1. Select “Internet Options” from the View menu.
2. Click on the “Advanced” tab.
3. Scroll down to find “Cookies” within the “Security” section.
4. To enable:
   1. Select “Always accept cookies”.
5. Click “OK”.

Mozilla Firefox (1.0 final release and earlier)

1. Go to the “Tools” menu.
2. Select “Options”.
3. Select the “Privacy” icon in the left panel.
4. Check the box corresponding to “Allow sites to set cookies”.
5. Click “OK” to save changes.

Netscape 7.1/Mozilla 5.0

1. Select “Preferences” from the Edit menu.
2. Click on the arrow next to “Privacy & Security” in the scrolling window to expand.
3. Under “Privacy & Security”, select “Cookies.”
4. Select “Enable all cookies”.
5. Click “OK”.

Netscape Communicator 4.x

1. Select “Preferences” from the Edit menu.
2. Find the “Cookies” section in the “Advanced” category.
3. To enable:
   1. Select “Accept all cookies” (or “Enable all cookies”).
4. Click “OK”.

Opera 7.x

1. Click on the Tools-menu in Opera
2. Click on the Preferences… item in the menu – a new window opens
3. Click on the Privacy selection near the bottom left of the window.
4. The Enable cookies checkbox must be checked, and Accept all cookies should be selected in the “Normal cookies” drop-down.
5. Save changes by clicking Ok.

Opera 9.x

1. Click on the Tools-menu in Opera
2. Click on the Preferences… item in the menu – a new window opens
3. Click on the Advanced selection on the top of the window. Then select Cookies from the left hand side
4. The Enable cookies checkbox must be checked, and Accept cookies should be selected
5. Save changes by clicking Ok.

Safari

1. Click on the Safari-menu in Safari
2. Click on the Preferences… item in the menu – a new window opens
3. Click on the Security icon near the top of the window.
4. Under Accept Cookies the Always or Only from sites you navigate to must be selected.
5. Save changes by clicking Ok.

Reduce the Image Quality:
Although this sounds like a disadvantage, it actually is not since digital pictures usually have a far higher resolution than any computer monitor can display. By reducing the resolution, or the number of pixels displayed per square inch (dpi), you can effectively optimize the image for both display and download purposes.

Crop Images:
Photos and other graphics often have more surrounding detail than is needed for your purpose. Zero in on the subject of your picture by cropping away any unnecessary white space or clutter. This will reduce the picture size (and load time) while focusing the visual impact directly on the subject matter.

Resize Images:
This one is easy. Why post a huge photo on a web page when a smaller one will serve just as well? Just resize the height and width of the photo in whatever graphics program you use on your computer before uploading it to your server. Do NOT simply reduce the height and width dimensions in your html code as this continues to use the huge file size and merely displays it in a smaller area of the page.

Image Optimizing Tools:
There are some excellent tools available for optimizing images, and one of the best is Irfanview, at http://www.irfanview.com, a free download that enables quick and easy image compression, cropping and resizing.

Click here for Adobe Photoshop CS2! .If you have Adobe Photoshop, you might want to read the optimizing images tutorial at http://catalyst.washington.edu/catalyst/how-to/scanning/minimizeImages.html which has excellent step-by-step instructions.

There are also free online tools. Netmechanic offers free sample use of GifBot, at http://www.netmechanic.com/products/GIFbot_FreeSample.shtml, which displays optimized versions of any image you upload, ranging from 90 percent down to 10 percent compression. MyImager, at http://www.myimager.com, is an online image editor with many different effects options, plus the capability to reduce colors in gifs and reduce quality in jpg format. There are many others – just search for “online image optimizer” in Google for more options.

One caveat – never optimize the original image!
Save a copy instead, and optimize that version so the original is always available in the future if you need it again.

Re-Using Images:
A common mistake among web hosting beginners is uploading the same image into multiple image folders. If your web site has several different directories, each with its own image folder, it might seem logical to upload the logo.gif into each image folder and call it into a page with a link relative to that directory. But consider – if you do this, then your server must reload the logo image every time a visitor moves from one directory on your site to another. Instead, use the same image path every time you use the image. That way, the server loads just one image which is then cached on the visitor’s computer and re-used for each page that displays it. This can greatly improve page load time if you have a number of common images, such as a logo or menu buttons.

Choose the Right Image Format:
Most web images are created as either gif files or jpg (or jpeg) files. There are pros and cons to both. Basically, gifs are best for simple graphics or line drawings. They can be created with a transparent background or used in simple animations and are often optimized by reducing the use of colors. The jpg format is better for photographs or full color images, but cannot be animated or used with a transparent background. For more detailed information on this topic, including side-by-side sample images, read David Eisenberg’s informative article, “Why Good Images Go Bad – A Guide to Effective Use of Images on Your Website” at http://www.catcode.com/imgguide/index

Some basic features that are common to all CMSes:

Separation of content, structure and design

A CMS improves the lifecycle of your website for years to come. The “look and feel” of your site can be changed or relaunched, leaving existing content and page architecture untouched. No need to worry about copying and pasting content into another site, simply publish your new design and the CMS will pull the content into the new look.

Easy content production, no programming skills required

If you can use a computer, you can manage the content for your website. Using a graphical user interface, authors can simply create text, insert images an multimedia files, schedule content (and much more) to build and maintain a dynamic website.

Just imagine: You will never need to make another menu button again, or pay a web designer to do it for you. Each time you add or change a page, the menu will automatically update to reflect the change. Having to learn or purchasing photo editing software will not be necessary. You can upload images straight to the web from your digital camera / DV camera or a scanner.

Common advantages of a CMS:

• Decentralized maintenance.
  Typically based on a common web browser. Edit anywhere, anytime. Bottlenecks removed.
• Designed with non-technical content editors in mind.

  People with average knowledge of word processing can create the content easily. No HTML skills required.

• Configurable access restrictions.
  Users are assigned roles and permissions that prevent them from touching content in which they are not authorized to change.
• Consistency of design is preserved.
  Because content is stored separate from design, the content from all authors is presented with the same, consistent design.
• Navigation is automatically generated.

  Menus are typically generated automatically based on the database content and links will not point to nonexistent pages.

• Content is stored in a database.
  Central storage means that content can be reused in many places on the website and formatted for multiple devices (web browser, mobile phone/WAP, PDA, printer).
• Dynamic content.
  Extensions like forums, polls, shopping carts, search engines, news management are typically drop-in modules. A good CMS also allows for truly user defined extensions.
• Daily updates.

  You do not need to involve web designers or programmers for every little modification - you are in control of your website.

• Cooperation.
  Encourages faster updates, enforces accountability for content editors via log files and promotes cooperation between authors.
• Content scheduling.
  Content publication can often be time-controlled; hidden for previews; or require a user login with password.

If you are promoting your graphic design business and have a page on business card design, stay on the topic and refrain from using a page title such as “Graphic Design company in Vancouver, Canada – business cards, logos, letterheads”. Your want the business card design to be the most important key phrase.

There are two main reasons for content relevancy. The first is so that visitors have an easy time understanding the flow of your web site. Visitors who have to search through multiple pages to find the information they’re looking for won’t be visitors much longer. The average web site user takes about three seconds to decide whether or not stay on a site. A clear idea of what your site is about should be apparent immediately, followed by easy navigation to other pages that display further topics in more detail.

The second reason for keeping content relevant throughout your web site is for search engine algorithms. Keyword relevancy is an important part of search engine optimization. The more relevant your web site’s content is for a specific term, the more likely the site is to show up near the top of search results for the term.

Keyword density is another big deal with search engines. There is an optimal ratio of key terms to the overall amount of text that must be used for search engine optimization purposes. The more unrelated terms that are used consistently throughout the content will bring down the percentage of more important keywords. Keyword density matters throughout an entire web site, not just on certain pages.

Other areas to keep an eye on are the contact page, about us page, and any other pages that you may not think are important to have optimized for search engines such as advertising info, privacy policy, etc. For instance, some web sites have pages devoted to reciprocal links. There’s nothing wrong with them unless you link out to a lot of unrelated web sites. The keywords that are used in the anchor text and surrounding description text will detract from your overall site content if they are not related. Incoming links from unrelated sites are fine, but keep in mind that the links page counts as part of your web site as a whole.

Consider using a reciprocal links page as more of a resource for visitors instead of a long list of irrelevant sites. This not only appeases search engines but your visitors as well. And as mentioned before, both visitors and search engines should be kept in mind when creating web site content.

In this article I’ll focus on PHP, the technology Oracle has chosen to incorporate into its products, and ASP.NET. I’ll overview the various strengths and weaknesses of each, discussing in particular those areas that will help you make your decision on which to go with for your development project. There are a lot of factors to consider, and different projects may appeal to a different technology. In conclusion you’ll find a point-by-point comparison in terms of price, speed and efficiency, security, cross-platform support, and the advantages of an open source solution.

What is ASP.NET?

The latest incarnation of ASP, ASP.NET, is not completely backward-compatible with previous versions of ASP, as it is a complete rewrite of the software. Previous ASP technology actually has a lot more in common with PHP than with ASP.NET, which is a complete framework for building Web applications. One of the principal features of this model is the flexibility to choose your programming language. ASP.NET works with scripted languages such as VBScript, JScript, Perlscript, and Python, as well as compiled languages such as VB, C#, C, Cobol, Smalltalk, and Lisp. The new framework uses the common language runtime (CLR); your language source is compiled into Microsoft Intermediate Language code, which the CLR then executes.

The framework also provides for true object-oriented programming (OOP), and true inheritance, polymorphism, and encapsulation are supported. The .NET class library is organized into inheritable classes based around particular tasks, such as working with XML or image manipulation.

Besides the programming language and the methodology, database access is a significant concern. When you program in ASP.NET, integration with databases can be accomplished through ODBC, which provides a consistent set of calling functions to access your target database.

Strengths and Weaknesses

ASP.NET’s strength lies clearly in its clean design and implementation. It is an object-oriented programmer’s dream, with language flexibility, and with sophisticated object-oriented features supported. In that sense, it is truly interoperable with your programmers’ existing skills.

Another strength of ASP.NET is the development environment. For instance, developers can use WebMatrix, a community-supported tool, Visual Studio .NET, or various Borland tools such as Delphi and C++ Builder. Visual Studio, for instance, allows setting of breakpoints, tracing sections of code, and reviewing the call stack. All in all, it’s a sophisticated debugging environment. Plenty of other third-party IDE solutions for ASP.NET are certain to surface as well.

But what you gain in robustness, you pay for in efficiency. ASP.NET is expensive with respect to memory usage and execution time, which is due in large part to a longer code path. For Web-based applications, these limitations can be a serious problem, because on the Web, your application is likely to scale to thousands and thousands of users per second. Memory usage can also become an issue on your Web server.

What is PHP?

PHP is a scripting language based on the model of preprocessing HTML pages. When the PHP preprocessor in your Web server notices a PHP language tag like the following, the PHP engine is invoked to execute that code:

< ?php
some code here
?>

PHP will be familiar to any programmers who have worked with imperative programming languages; you’ll notice syntactical similarities with Perl, C, and Java. Strictly speaking, Java is an imperative programming language, but it also makes use of object-oriented constructs and concepts. PHP borrows from this structure when it is convenient, but it is not a pure OOP language.

In the discussion of ASP.NET above, I mentioned the ODBC driver, and how applications can be built with database abstraction in mind. In PHP, you can also use ODBC to talk to databases, so you already have a whole list of supported databases to choose from. There are also native drivers for MySQL, Oracle, and Postgres. Furthermore, if you are connecting to Oracle, a special OCI8 library provides more feature-rich access to Oracle, allowing you to use such features as LOB, BLOB, CLOB, and BFILE.

You might ask, at this point, “Why are database-dependent libraries being touted as features of PHP?” Database abstraction, or independence, is a feature if you seek to build an application that works with multiple databases in one application or that can easily be ported to another database—when moving from development to production, for instance. And these are indeed valid concerns and considerations.

But, as Tom Kyte points out in his latest book, Effective Oracle by Design (Oracle Press), database dependence should be your real goal because you maximize your investment in that technology. If you make generic access to Oracle, whether through ODBC or Perl’s DBI library, you’ll miss out on features other databases don’t have. What’s more, optimizing queries is different in each database.

Zend Technologies, a commercial software company that contributes significantly to PHP, has created a commercial-development environment called Zend Studio that includes a sophisticated debugger, a profiler, and other features. It has also built the free Zend Optimizer, which, in combination with the Zend Encoder, compiles PHP code to speed performance. Additional commercial products also exist, such as the Zend Performance Suite, which can cache precompiled PHP pages, further speeding overall performance tremendously.

Strengths and Weaknesses

As of beta version 4, PHP 5 still has a few shortcomings, including its lack of exceptions, event-based error-handling instances that interrupt the normal flow of a program, jumping your code to a special error-handling section. Java also provides exceptions for error handling, while C++ provides exception handling via the try, catch, and throw syntax. You can, of course, still manage errors in PHP, but the structure is not standardized, so programmers are left to their own devices on how to implement error handling, leading to less consistency and a tendency to reinvent the wheel.

Another weakness is that PHP’s function names are case insensitive. Some programmers might find this feature annoying, though this isn’t a serious drawback.

I do have misgivings about PHP’s object model, however. PHP wasn’t designed to be an object-oriented language. Some of those features were added later, although care was made to keep backward compatibility with PHP 3, so you’re left with a bit of both models. In fact, many of these weaknesses are addressed in PHP 5. Keep your ears to the ground.

What PHP lacks in a few areas, it makes up for by leaps and bounds in areas in which it excels. The price is right, so you don’t have to worry about licensing issues. It’s open source, too, so an entire community will keep a close eye on development, identifying bugs and making sure they get fixed. And if there’s a feature you don’t like, you can dabble with the code. What’s more, PHP works native with Apache: It can be compiled as a module or directly into the Apache binary.

But running on Apache means that, with PHP, you can take advantage of whatever server investments you’ve already made, because Apache runs on Windows, Linux, Solaris, and various other Unix platforms. Also, going with a web server with Apache’s track record means security remains a top priority. And, finally, PHP has a smaller code path, meaning there’s less server-side code executed to parse and execute your PHP page, which results in more efficient memory and usage and faster execution.

What’s New in PHP 5?

The fourth beta release of PHP 5 came out at the end of December 2003, and the change log makes it obvious that many bugs are being identified and ironed out. Although it’s still in beta, it’s definitely worth taking a look at for all the new features and advances.

PHP 5’s major new achievements come in the area of its exception handling and a new object that introduces features that bring true OOP to PHP. Exception handling was certainly one of the most noticeable missing features in PHP 4, and its addition to PHP 5 is certainly a sign of maturity. Exception handling means you have language defined and standardized ways of handling errors in your software. Just use the try, catch, and throw methods, and your PHP code becomes more robust and clean.

< ?php

class blue {

function openFile ($inFile) {
if (file_exists ($inFile)) {
# code to open the file here
} else {
throw new Exception
("Cannot open file: $inFile");
}
}
}

$blueObj = new blue ();

try {
$blueObj->openFile (’/home/shull/file.txt’);

} catch (Exception $myException) {
echo $myException->getMessage ();

# rest of exception handling code here
}

# rest of blue methods here

?>

The new object model has a number of positive impacts on programs written in PHP. In PHP 4, when an object was passed to a function or method, it was passed by value, unless you explicitly told PHP otherwise. This procedure meant that a copy of that object, all the data structures in memory, would have to be copied. This step used memory and made access slow and clunky. In PHP 5, however, objects are always passed by reference.

The new object-oriented features in PHP 5, including constructors and destructors, are noteworthy. As with C++ and Java, they provide a standard way to create the object, allocate memory, and do any necessary setup via a constructor method and perform cleanup with a destructor method.

PHP 5 also introduces more subtle control of methods and variables in your classes. In PHP 4, everything was public: You could access variables from your classes outside the class or in derived classes. In PHP 5, you can still make variables or methods public, but you can also make them private, so they’re used only within the class itself. A third option is to make them protected, which means that methods and variables can be viewed within the class or when subclassed.

Furthermore, PHP 5 introduces type hinting, or better type checking. When you pass an object into a routine, PHP can check that it is the right type and give a type-mismatch error if the check fails.

Additional features such as static methods and variables and abstract classes exist, so be sure to check the documentation for details.

Security Comparison

ASP.NET officially requires that you use IIS. Unfortunately, IIS has a long history of vulnerabilities, which makes many administrators reluctant to deploy it to handle their web site. Whether these weaknesses are because of Microsoft’s ineptness or because IIS is a real red flag to hackers is irrelevant: Those systems have a history of being hacked and compromised. PHP runs on Apache, too, which is fast and open source and has a good security track record. Also, as I mentioned, Apache runs on many platforms.

If you are considering ASP.NET but you want to use Apache for your front-door to the Internet, you are fortunate to have a few options. First, you can use Apache to relay requests to IIS running internally on another machine. Apache then handles static content and passes aspx content on to the IIS server, which isn’t exposed to the internet.

However, if you want to host ASP.NET with Apache, a couple of options are available that may or may not be supported by Microsoft. As a last alternative, there is Ximian’s Project Mono, which is working to build an open-source module. Check www.go-mono.com for more information.

Database Coding Examples

Connecting to a database is one of the first things you’ll consider doing in PHP or ASP.NET. With ASP.NET, however, it’s a little more complicated, because you have the option of any of a number of languages to choose from. Of course, these code samples would have to be embedded into an HTML page, the classes instantiated, and so on. The following information, however, will give you an idea of the coding styles for each.

PHP 5 Connecting to Oracle

Here’s a PHP 5 class that provides an Oracle connect-and-disconnect routine to show one way of connecting to Oracle with PHP 5 (other drivers, such as the ODBC driver, and generic database interfaces can be used as well):

class oracle_object {
protected $theDB;
protected $user;
protected $pass;
protected $db;

function __construct($u, $p, $d) {
$this->user = $u;
$this->pass = $p;
$this->db = $d;
}

function db_open () {
$theDB = @OCILogon($this->user, $this->pass, $this->db);
db_check_errors($php_errormsg);
}

function db_close() {
@OCILogoff($theDB);
db_check_errors($php_errormsg);
}

function __destruct () {
print (”so long…”);
}

}

ASP.NET Connecting to Oracle

If you’re looking to connect to Oracle with VB.NET (Visual Basic is Microsoft’s default .NET programming language), take a look at this sample from MSDN:

Imports System
Imports System.Data
Imports System.Data.OracleClient
Imports Microsoft.VisualBasic

Class Sample

Public Shared Sub Main()

Dim oraConn As OracleConnection = New OracleConnection(”Data Source=MyOracleServer;Integrated Security=yes;”)

Dim oraCMD As OracleCommand = New OracleCommand(”SELECT CUSTOMER_ID, NAME FROM DEMO.CUSTOMER”, oraConn)

oraConn.Open()

Dim myReader As OracleDataReader = oraCMD.ExecuteReader()

Do While (myReader.Read())
Console.WriteLine(vbTab & “{0}” & vbTab & “{1}”, myReader.GetInt32(0), myReader.GetString(1))
Loop

myReader.Close()
oraConn.Close()
End Sub
End Class

Making the Choice

Without assuming you’ve already decided to go with PHP, I’ll conclude that its strengths far outweigh its weaknesses. (See the summary in Table 1.) It boils down to price, speed and efficiency, security, cross-platform applicability, and open-source opportunity. Its only weakness is its lack of a pure and perfect OOP implementation; however, this is a minor drawback. Though language constructs do help, ultimately, good coding is a matter of practice, execution, good habits, and discipline.

Price. Here, we must consider not simply the price tag of the initial investment, which, in the case of PHP, is obviously free, but also the implementation, maintenance, and debugging costs. In the case of PHP, you may invest in the Zend optimization engine. With ASP, however, you’re investing from the very beginning, and you’re spending for add-on technologies—libraries for doing graphics manipulations, for instance. But, in the long term, PHP isn’t going to press you to upgrade and collect more licensing fees. Everyone who has dealt with complex licensing also knows that companies spend time and money just ensuring they are compliant. Furthermore, you have a difference in response when getting bugs fixed. This, of course, translates to time, which translates to cost for overall development.

Speed and efficiency. As I mentioned earlier, ASP.NET is a framework allowing you to use various programming languages. In addition, it is touted as having a great object-oriented model. All this is true, but it becomes a detriment as far as speed is concerned. For all that advantage, there is a lot more code to run through to execute the same ASP page than you have to execute in the PHP engine for an equivalent PHP page. PHP is the quick-and-dirty type of solution, the one to get the job done. And though a lot of robustness has been added to it since its 2.0 and 3.0 days, it still retains that core optimized high-speed approach.

Speed is not the only consideration. Memory usage is also important.

Security. ASP.NET runs on IIS, which has been compromised innumerable times, as evidenced by IT news reports every other week. It has become such a liability, in fact, that in spite of all the marketing dollars spent on it, many IT professionals refuse to have their networks exposed with an IIS Web server. PHP, however, works with Apache, which has a proven track record of speed, reliability, and hardened security. Check www.securityfocus.com for more information.

Cross-platform applicability. ASP.NET runs on IIS and is starting to run on Apache, which can run on a whole host of platforms. PHP has been designed to work with Apache from the beginning, so you have many proven and reliable server platforms to choose from.

Open source opportunity. Open source is not just some philosophical torch idealistic programmers, or companies wanting to save a few bucks on licensing costs, are carrying. When you’re dealing with bugs in the software itself, open source can be a serious godsend.

In either case, with PHP or ASP.NET, you have a large user base using the software and possibly encountering bugs. With ASP.NET, those bugs have to go through a bureaucratic process to get acknowledged, fixed, tested, and rolled out in a new patch or release. PHP fixes, however, can get fixed quickly and rereleased. Anyone who has watched open-source development knows new releases and patches often come out in days rather than in weeks or months, as with commercial software. If that’s not fast enough, you can always fix a problem yourself if you have to.