I think my biggest pet peeve of August 23 2003 - August 23 2004 is the common Java practise of meta-programming with XML. I am all for letting users configure frameworks with their own classnames and if this is machine generated by a visual config editor, than it can be in XML, but don't make users write XML by hand. Worse is scripting in XML using declarative elements and testing attributes, like with ant. This is awful.

XML is great for applications to talk to each other, and we can humans can eavesdrop, but write a parser for a mini-configuration language, or reuse an existing standard, for files edited by hand!

Struts and Ant are the poster children for this problem. They should support a config in xml and a more programmer/sys admin friendly format, that compiles down to build.xml files. If your lazy, that's ok have it do python/other scripting language variables in a file <==> build.xml