Hello, everyone.

I want to write simple graphical front-ends (I'd rather say, GUI wrappers) for some command-line programs.

What combination of programming/scripting language + GUI library could you recommend?

Necessary:
1. Support for both Linux and Windows without modification of code.
2. Easy call of command-line programs without showing their output to the user but with a possibility of processing the output in the program.

Preferably:
1. Support for MacOS.
2. Simpleness and high speed of development.
3. Good documentation and large enough community.
4. Object-oriented GUI library.
5. Dynamically created GUI (somehow structurally/logically, not by hand).
6. High speed of GUI on PC with slow CPU and primitive video card.

give QT a try.

The easiest way is python + tk (just import Tkinter and off you go). Tk itself isn't OO but python is so it's easy enough to use it in an OO manner. Even if you decide not to use it for the final app, it's great for prototyping.

If you want to end up with a compiled binary, the standard choices are Qt, as matthewg42 mentioned, and GTK, both of which should work in Windows as well as unix, there isn't a great deal between them from a user's point of view, so it will basically boil down to whether you want to use C++ (Qt) or C (GTK), though there are also C++ bindings for GTK (gtkmm).

There are others of course, such as FLTK, though most distros may not include these by default.

If you want a "native" look, have a look at wxWidgets, which is a platform independent frontend (in C++) to each systems' natvie GUI (defaults to GTK on Linux I believe).

If you want compiled language, then I recommend C++/Qt 4 (my favorite GUI library). If you want really good-looking GUI, then (I think) Qt will be best choice.

Alternatives to Qt include wxWidgets, FoxToolkit, FLTK, GTK, but I do not know which of those libraries support MacOS and never used any of those libraries much.

IF you want scripting language, then take a look at python. It should have some built-in (i.e. standard) GUI functionality (see python docs), which should be supported on several platforms and included in standard python distribution. And there are also extensions like wxPython, pyQt, PyGTK, etc.

I have found that python + wxPython is really easy to use. There is really good documentation out there for it, and even though I hadn't done any programming in python previously, I was able to pick it up pretty easily just by reading the examples. wxWidgets (wxPython is a wrapper for wxWidgets) has lots of built in widget types, so you really don't need to write all that much code yourself.

I think I forgot to add one preference to my points: it is desirably that GUI will be created dynamically (somehow structurally/logically, not by hand).

Thanks for your replies.

I think I'll try tk + Python or Tcl. Do you know if my necessary point 2 (processing of console apps' output) is possible and cross-platform in these languages?

That shouldn't be a problem with any of the suggestions, AFAIK.