Boot is a Clojure build framework. Here is an example of a basic ring application that is run using boot. The project folder is shown below.

ring-helloworld
├── build.boot
└── src
    └── net
        └── jsloop
            └── server
                └── core.clj

;core.clj
(ns net.jsloop.server.core
  (:require [ring.adapter.jetty :as jetty]))
 
(defn handler [req]
  {:status 200
   :body "Hello World"})
 
(defn -main [& args]
  (jetty/run-jetty handler {:port 8080})

;boot.clj
(set-env!
  :source-paths #{"src"}
  :dependencies '[[org.clojure/clojure "1.8.0"]
                  [ring "1.5.0"]])
 
(require '[net.jsloop.server.core :as server])
 
(deftask run []
  (with-pre-wrap fileset (server/-main) fileset))

From the project root, run the server using boot.

boot run

Open http://localhost:8080 to see the response.