[irahul]

To add to the list, Peter Norwig's lisp interpreter is a short, concise introduction to interpreters.

http://norvig.com/lispy.html

http://norvig.com/lispy2.html

[zerd]

Another one I recommend, because it starts with codegen and works its way back:

Writing a compiler in Ruby, bottom up: http://www.hokstad.com/compiler