# 1 What is GNUstep Renaissance

GNUstep Renaissance is an advanced framework for creating portable user interfaces. It works on top of gnustep-gui (and of Mac OS X Cocoa under Apple), and provides an easy and powerful way to create and manage user interfaces.

In our previous tutorials we have learnt how to create user interfaces by hand, writing code which creates all the objects in the user interface. GNUstep Renaissance simplifies considerably this task. Instead of writing all the code yourself, you write a simple file (in a format called gsmarkup) which describes (very simply) the interface. At run time GNUstep Renaissance can create all the interface from the file, including all size and layout computations, and then connecting the objects created in the user interface with the objects in the application as required.

By using GNUstep Renaissance you can create quickly user interfaces which build and run on both GNUstep and Apple Mac OS X, without changes in source code. This is not possible with traditional nib and gorm files.

In this tutorial you'll learn how to create and edit gsmarkup files, and use GNUstep Renaissance to load them into programs.

GNUstep Renaissance will have an interface builder clone program written for it, which will for the most part obsolete creating and editing the gsmarkup files directly. This program will allow you to edit gsmarkup files by viewing a graphical representation of the gsmarkup contents, and dragging and dropping objects into it. This tutorial will be partially obsolete then; but it will still be of use to anyone wishing to learn something about the GNUstep Renaissance gsmarkup format and files.