The UNIX world is crippled because there are no easy-to-use user interfaces. Well... in the last few years, a lot of text-based and graphical-based, too, user interfaces has appeared. The only problem is that they are written by programmers for programmers. So, the ordinary users don't use UNIX because they think UNIX systems are hard to use. Of course, the command line, the pipes, and so on, are very useful, but they does not attract the ordinary users. These users needs intuitive, easy-to-use user interfaces, so to simplify their work.
So, we should combine the power of UNIX with the easy-to-use property of some user interfaces. This will allow the users to have both a powerful and a real operating system and a easy-to-use user interface.
Xterminal is a user interface. A text-based one.
Why a text-based user interface? The text-based user interfaces are very useful for applications that runs on non-graphic-capable terminals, and for utilities that just don't need a graphical interface.
During the last few years, object oriented programming have become very popular. That's because of a lot of advantages which helps the development of today's projects, that are becoming more and more complex. It makes the applications to split into several modules, so the developer of a module don't need to have knowledge of the other's implementation details.
Last but not last, the object orientation is a very natural paradigm. In the real world, day by day, we are dealing with Objects. Everywere around us are objects, which are interconnected, and which are communicating using Messages.
The client-server architecture is a very popular paradigm, too, nowadays. That's because of it's natural design, of course. Now, for example, I am speaking, so I'm a server, and you are listening to me, so you are clients. And we are communicating using messages.
The message communication is very important, generally in client-server designed applications, and particulary in Xterminal.