In visually testing interfaces where code might live what do you use for your particular language for a standard? "Hello World" is not sufficiently complex enough in most cases. I am particularly interested in Perl but C#, C, C++, and Java are coming up.
Per the comment:
Lets say you created a new IDE, color scheme, or a web page where code will be placed by you or others. You want to see what your changes look like with stuff that looks like with typical code. Lorem Ipsum is used by type setting programs but it isn't really code.
I'd suggest you create a code sample for each such language you're interested in, and have it in a file.
e.g. sample.c, sample.py, sample.java, etc.
Editra uses such files to test syntax coloring and stuff.
http://svn.wxwidgets.org/svn/wx/wxPython/3rdParty/Editra/tests/syntax/