Most template tools made the major mistake of existing. They start out as some attempt to limit the functionality available in templates but pretty soon they al

Most template tools made the major mistake of existing. They start out as some attempt to limit the functionality available in templates but pretty soon they always add functions and conditionals and formatters etc... ending up with what is essentially a turing-complete language, except needing an extra step to parse, less well tested and usually much uglier than the host language. Oh, and you have to learn it as well, because someone had a fetish of avoiding python/php/perl/... in templates, inventing <loop start=1 end=15 step=1> to replace (1..15).each. Nowadays we're replacing loops with recursion or map but fundamentally, there's no difference. If you have a collection and you want to render it, you need the logic of repetition in a template, and there's nothing wrong wit h putting it there. 10 years ago, you would often see html with interspersed business logic, even SQL. That just doesn't happen anymore. Now, fruitless attempts to further reduce logic in templates just lead to convoluted overengineering who at best try to hide the logic.