Jim Thomason has an excellent writeup at Perl Monks called The History of a Templating Engine. It’s almost a rite of passage for Perl programmers to write a simple templating system, and novice programmers somehow universally fail to understand why writing yet another templating system is an exercise in pain, frustration, and usually unmaintainable, unremarkable code. Jim’s account of the evolution of his system and the lessons he learned is, hopefully, a great bucket of cold water to cool those youthful urges.