<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.