What is it?
Apache is far and away the most popular web server, with more than double Microsoft's market share. But perhaps market share is the wrong term, since anyone can download and install Apache free of charge. It is an open source product, maintained by the the Apache Project, which describes itself as "a collaborative software development effort aimed at creating a robust, commercial-grade, featureful, and freely available source code implementation of an HTTP web server."
Like Linux, Apache is managed by a core of dedicated developers around the world, linked by the internet. The Apache people believe the tools of online publishing should be open to everyone, and software companies should make their money by providing value-added services. They are fiercely opposed to the idea of one company owning the protocols through which we all communicate.
Where did it originate?
In 1995, at the National Center for Supercomputing Applications (NCSA), University of Illinois, eight people took over responsibility for an existing HTTP server which had been languishing since its creator left the NCSA. They added all the outstanding patches and enhancements, and released it as version 0.6.2 of the Apache Server ("a patchy server").
The Apache Software Foundation was formed in 1999 to provide organisational and financial support for Apache, which by then was running on 57% of the world's web server hardware.
What is it for?
It is a highly configurable HTTP/1.1-compliant web server which can be extended with third-party modules or customised with modules written using the Apache application programming interface. It can be configured as a proxy server, and support for Java and Active Server Pages can be added.
What makes it special?
Apache may or may not be the fastest web server - benchmarks can be selected to suit the strengths of particular products. The Apache view is that it is better to have a fairly fast free server than an extremely fast server costing thousands of pounds.
Apache has had its share of bugs and security vulnerabilities, but the involvement of a worldwide community means these are found and fixed extremely quickly.
How difficult is it to master?
One regular complaint is the lack of graphical user interface tools to make it easier to use.
Where is it used?
Apache has been widely taken up by commercial companies. Like Linux, Apache is now backed by some heavyweight software companies. Paid-for commercial support is available for the nervous, and Apache is bundled with the Oracle database and Borland's Kylix and Delphi development tools.
Not to be confused with...
A military helicopter. A guitar instrumental by the Shadows.
What makes it hot?
According to the Netcraft Web Server Survey, in May 2003, Apache was running on 62.5% of the world's web servers, Microsoft products on 27%, Zeus on 2%, and Sun One on 1%.
What systems does it run on?
Most versions of Unix, Linux, Windows, 0S/2 and other operating systems.
What is coming up?
There are regular minor releases of Apache as bug fixes and new features are added. The Apache Project receives about 40 contributions a day from the developer community.
There are lots of tutorials on the web. A good starting place is www.apache.org
Rates of pay
Apache skills are used in web development, systems administration and support, and there is a wide range of salaries.
This was first published in June 2003