Something I discovered yesterday is how easy it is to add code
completion functionality to any XML file. Say, for example, you
work a lot with datasource configuration files for JBoss. It's
really easy to set things up so that, while typing, a little
drop-down such as the following appears to suggest tags to use:
To create that list, all you need is a DTD file. Code completion
for XML files is based on the DTD file declared in the second line
of the XML file. But, there's...
