In this post I'll cover the setup I use for developing my Compojure/GAE app.
Of course you can use any editor you like to edit your source code, but Emacs has some great features for editing Lisp code that make developing in Clojure a pure joy. When properly set up, you can add new or modify existing code and inspect all your data while the application is running.
I followed the instructions at http://technomancy.us/126 to set up Slime/Swank for Clojure and it worked flawlessly without any modifications. I can also recommend the Emacs Starter Kit that is mentioned in the above post.
There are several options for getting the clojure.jar that you'll need:
clojure-install command.You can download a tarball of the Compojure sources from http://github.com/weavejester/compojure/downloads, but I'd recommend cloning the git repository at http://github.com/weavejester/compojure. Either way you'll build the compojure.jar from source using ant.
Compojure has a few dependencies. You can download a zip file containing all needed jars (including clojure.jar and clojure-contrib.jar) from the download link above, or you can just run ant dep, which will download the zip for you.
Download the latest GAE SDK from http://code.google.com/appengine/downloads.html. Choose the SDK for Java and unzip it somewhere.
In the next post I'll create a simplistic Hello World Compojure app.