server. Developers are granted access to this repository only indirectly through formal check in 

and checkout of code. The idea is that all developers work with their own local copy of source 

code, and only check their code in once it compiles and runs. Versioning control systems keep 

track of who is currently working on which files, and therefore prevent developers from 

accidentally deleting or overwriting one another's code. In addition to that, the repository keeps 

a complete history of all versions of the source code, so any version of a file may be retrieved 

later on, or the differences of any two versions can be analyzed. 

The dominant versioning control system today is an Open Source Unix/Linux command line tool 

called Concurrent Versions System, or short CVS. It is widely used in both the Commercial and 

the Open Source software development world. CVS is based on RCS (Revision Control 

System). 

Most Linux distributions ship with CVS. The versioning control system tools may also be 

downloaded from Web sites (e.g. 

http://www.cvshome.com

) as source code, or as binary 

version for all common operating systems.  

3  Introduction to Web Application Development 

Chapter 2 gave an overview on current Open Source products and their features. This section 

deals more with the technical aspects of selected Web application development technologies, 

which should give the reader a good starting point for further study of the subjects. 

The author assumes that the software packages described in this section have been 

successfully installed. Detailed installation instructions are available on the Internet for each of 

the products. 

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