Up until about 1995, a standard for software that performed auxiliary processing existed. It was called the Common Gateway Interface (CGI). Every type of server-side processing required the Webmaster to write a script in Perl, C, or C++. The script was saved with an extension of .cgi. When the Web server saw this extension, it read only the first line of the file and passed the script on to the appropriate compiler. Advantages to this system were: All three of these languages were commonly found on UNIX, most Web servers up until 1995 were UNIX based, and compilers for all three of these languages were in the public domain and likely to be found on your UNIX server.

The disadvantages were and still are as follows:
> All three of these languages are programming languages
> A single page of HTML may take pages of code to generate
> Making a change to the HTML on a page requires a programmer
> Hours of programming produce relatively modest results
>today, many people who use CGI programs either use pre-existing programs and don’t make any programming changes to them, pay their ISPs to make programming changes, or are hardcore programmers.


Unfortunately, no standard exists in middleware. Quite a number of different types of systems are available to you as a Web developer to produce high-quality server side processing. Most middleware revolves around interacting with a database.

The advantages of using modern middleware include fast development time and the availability of rapid-application development (RAD) tools for many of these products. The disadvantage is cost. Most of them are commercial software. If you administer your own server, you can choose which one you like best. If you are already using an ISP with which you are happy, you will probably use one of the RAD tools it provides. Table 1-2 shows common extensions used to indicate that external processing is required.

Fig:

Rapid application development (RAD) tools are productivity-enhancing if they permit
> drag-and-drop access to data sources
> uniform-style application across all pages in your site or project
> multifile search-and-replace
> spelling check
> looking up of HTML tags
> auto-tag insertion
> Wizards and all without creating messy code.