# 3 Writing the gsmarkup file

We start by writing a gsmarkup file to create an empty window using GNUstep Renaissance:

    <gsmarkup>

      <objects>

        <window />

      </objects>

    </gsmarkup>

We save this code in a file called Window.gsmarkup. As you can easily see, the code – which is written in the gsmarkup format – is very similar to HTML; as a matter of fact, it is a variant of XML. There are tags (such as <gsmarkup>) and each tag is closed after having been opened (for example, </gsmarkup> closes <gsmarkup>). The syntax <window /> is equivalent to <window></window>, that is, the window tag is opened and immediately closed.

The code starts with <gsmarkup>, and ends with </gsmarkup>: it's all contained in a gsmarkup tag. This is equivalent to an HTML file, which starts with <html>, and ends with </html>.

Inside the <gsmarkup> tag, we find the <objects> tag. The <objects> tag enclose a list of tags; each of those tags represents an object which is to be created when the file is loaded.

In this case, there is a single tag inside the <objects> tag: the <window /> tag, which tells GNUstep Renaissance to create a single object – a window – when the file is loaded.