Macros haven't flown into mainstream languages, but they've been smuggled in through the back door. C++ templates were not intended to be as useful as they are,

Macros haven't flown into mainstream languages, but they've been smuggled in through the back door. C++ templates were not intended to be as useful as they are, but now many of the most powerful C++ libraries use templates as a compile-time metalanguage. Java library developers have also discovered the advantages of the transformation of data into runtime code - except they use XML as the data medium instead of s-expressions, and they use Java reflection to translate the XML instead of using "read" to get a Lisp object. Ruby and Javascript library authors use the metaprogramming capabilities of their respective languages in combination with XML or JSON or YAML data. Look at ruby on rails, or at jquery.