Hi there
Does anyone know any language except Java that can be used for constructing GUIs?(graphical user interfaces)

Thanks

Err lots? C, C++, Python, ...

There are very few non-trivial languages that don't have at least some library/module/whatever to allow GUI construction. Pretty much any language you would be interested in will have a number of ways to construct GUIs. Regardless of the languages, some of the popular ones are wxWidgets, GTK+, and Qt (they are available for all sorts of langauges, like C, C++, Python, Perl, Ruby, Java, etc. If you are using .NET (C#, J#, L#, VB.NET, etc), there is Windows.Forms, and the JVM has Swing (Groovy, JRuby, etc.).

Hi again
Do you actually know if GTK+ can make better GUIs than Java?
Thanks

That really depends on your idea of better. If you mean in terms of usability, only the GUI developers can make it better or worse, not the GUI toolkit. If you mean simpler to program for, I would say Swing is slightly easier. If you mean performance, GTK+ would win just because it is native. Though Swing apps can definitely be very fast. Do you mean in terms of "built-in" functionality (like video support, etc)? Well, both provide a very basic UI, then depend on third party developers to create extensions to handle more complex UI components. Do you mean technically? Well, that is very subjective. Swing's event-driven model is much more intuitive. It directly follows from the Observer pattern. Thus, it is easier to extend and manipulate. Both can easily build very complex GUIs. Overall, I would say the choice to use one or the other depends much more on other, more external, factors. If you are building an app to run on the JVM, it makes sense to use Swing, since you don't have to rely on the GTK+ library. If you want the speed of GTK+ on Java, look at SWT instead.

I would suggest PyGTK or Gtkmm. PyGTK is GTK+ binding for Python language and Gtkmm is for C++. They both are very powerful and easy to use.