Warbler is a gem that creates a web application archive (WAR) file from a Rails- or Rack-based application.
A WAR file is a special case of Java archive (JAR) file; both are really just zip files. But a WAR file is structured according to a standard that’s recognized by all Java web servers. You can take a closer look at this by extracting the WAR file you created in this chapter with any unzipping tool. Inside it, you’ll find these essential components (among many other things):
The top-level ...