sbt-pop makes development reloading faster and therefore much better. It uses the same type of mechanism that play uses (and borrows a lot of that code) to achieve "faster" reloads. Particularly, its functionality and requirements of user space code changes are as follows:

• Uses a series of hierarchical classloaders to trash in the event of a reload, well one specifically, the application classloader.
• Creates your class dynamically and instantiates it as a descendent of an interface (which is a java only project) which supplies the application classloader with the start method.
• Has a hook for shutting down, so you can gracefully close things like db connections, etc.
• Uses JDK7 watcher service, so jdk7 minimum.

• Add the plugin to your plugins.sbt file in your project. This brings in build-link runtime dependency which does not require scala.
• In the sbt project you want to use it, you'll have to call .enablePlugins(PopPlugin). and also set the mainClass in run := Some("your.main.class.NOT.OBJECT.which.inherits.from.Base").
• You can also watch extra projects like so:

If client is a scalajs project, this will add it to the watcher. At the moment the TaskKey[_] in the second _2 spot of the tuple doesn't do anything at the moment. It will scope the TaskKey[_] to the project specified in the first spot of the tuple.

popWatchedProjects ++= Seq(
    (thisProjectRef in client).value -> (fastOptJS in Compile)
),

• Make a class not an object, that inherits from com.dispalt.pop.Base
• Start your own custom server in the start(ClassLoader, port) method.

The classloader parameter is useful for things like the typesafe config, make sure to use the provided ClassLoader when dealing with ConfigFactory.load

• Destroy resources in the stop method.
• The reload method is unused at the moment.
• Port isn't also really necessary to set at the moment, but comes as a parameter.

• sbt-revolver - Forks and runs
• play - Great reload experience