I love this simple Common Lisp REPL by Stas Boukarev over at Zach Beane’s Common Lisp Tips. In just 5 lines of code you get a complete REPL that even handles *, **, and ***.
In the comments, Brit Butler adds two more lines that makes it display the current package as well. Good stuff.
I’ve mentioned Common Lisp Tips many times before and can’t recommend it enough. Xach always has something useful to say and, most often, something I didn’t know. If you’re a Lisper, you really should subscribe.