The Python language (www. may be less well-known, but is widely appreciated by Web cognoscenti. And Sendmail (, the most popular E-mail server program, also belongs to this select band, as does BIND, the main domain name system server software (see

The previous cultural divide between the free software community and business users was bridged in the most dramatic way by Netscape’s announcement in January that it would not only be giving away its forthcoming Communicator product, but making the source code available. That is, anyone would be able to take the program, modify it and then use it for any purpose.

In fact this free availability of the source code – rather than the zero price-tag – is the key defining characteristic of all the free products mentioned above. It is what makes such software so powerful.