Persistent JVM

If you've used the JVM for much time at all, you know that one of the worst things about it is the incredibly slow start-up time. This is even more apparent when you are running a build tool. Cake solves this problem by using persistent JVMs (one for Cake itself, and one for your project). When you run the cake script, it first makes sure the JVM is running, then it connects using a socket and sends your command. This makes interacting with your Clojure project blazingly fast. This also makes it really easy to open multiple REPL threads that all share a single JVM which is great for testing parallel code.

Cake tries to keep the persistent JVMs running as long as possible by reloading Clojure files that have changed. However, when .java, .class and .jar files change, Cake has to restart the project JVM. If you have existing REPL or Swank connections though, Cake will refuse to close the JVM, printing a warning instead.