Allen Holub (Author of Compiler Design in C and famous OO Guru) said: "XML is perhaps the worst programming language ever conceived. I’m not talking about XML as a data-description language, which was its original design. I’m talking about perverting XML for programming applications. It’s inappropriate to use XML as a scripting language (e.g., ANT), a test-description language (e.g., TestNG), an object-relational mapping language (e.g., Hibernate, JDO), a control-flow language (e.g., JSF), and so forth. These sorts of XML “programs” are unreadable, unmaintainable, an order of magnitude larger than necessary, and audaciously inefficient at runtime." Link