diff --git a/src/ludus/core.cljc b/src/ludus/core.cljc
deleted file mode 100644
index 83ff37b..0000000
--- a/src/ludus/core.cljc
+++ /dev/null
@@ -1,28 +0,0 @@
-(ns ludus.core
- 	(:require
-  		[ludus.scanner :as scanner]
-  		[ludus.parser :as parser]
-  		[ludus.grammar :as grammar]
-  		[ludus.interpreter :as interpreter]
-  		[ludus.show :as show]
-  		))
-
-(defn run [source]
-  (println (str "Running some ludus source: " source))
-  (let [scanned (scanner/scan source)]
-    (if (not-empty (:errors scanned))
-      (do
-        (println "I found some scanning errors!")
-        (println (:errors scanned))
-        )
-      (let [parsed (parser/apply-parser grammar/script (:tokens scanned))]
-        (println "Scanned: ")
-        (println scanned)
-        (if (parser/fail? parsed)
-          (do
-            (println "I found some parsing errors!")
-            (println (parser/err-msg parsed))
-            nil
-            )
-          (let [interpreted (interpreter/interpret source parsed)]
-            (show/show interpreted)))))))
\ No newline at end of file
diff --git a/src/ludus/loader.clj b/src/ludus/loader.clj
new file mode 100644
index 0000000..f8ba0a0
--- /dev/null
+++ b/src/ludus/loader.clj
@@ -0,0 +1,16 @@
+(ns ludus.loader
+  (:require [babashka.fs :as fs]))
+
+(defn cwd [] (fs/cwd))
+
+(defn load-import
+  ([file]
+   (let [path (-> file (fs/canonicalize) (fs/file))]
+     (try (slurp path)
+          (catch java.io.FileNotFoundException _
+            (throw (ex-info (str "File " path " not found") {:path path ::error true}))))))
+  ([file from]
+   (load-import
+    (fs/path
+     (if (= from :cwd) (fs/cwd) (fs/parent (fs/canonicalize from)))
+     (fs/path file)))))
diff --git a/src/ludus/repl.clj b/src/ludus/repl.clj
new file mode 100644
index 0000000..6455f48
--- /dev/null
+++ b/src/ludus/repl.clj
@@ -0,0 +1,124 @@
+(ns ludus.repl
+  (:require
+    [ludus.scanner :as scanner]
+    ;[ludus.parser :as parser]
+    [ludus.parser-new :as p]
+    [ludus.grammar :as g]
+    [ludus.interpreter :as interpreter]
+    [ludus.prelude :as prelude]
+    [ludus.show :as show]
+    [ludus.data :as data]
+    ;[ludus.process :as process]
+    ))
+
+(declare repl-prelude new-session)
+
+(def sessions (atom {}))
+
+(def current-session (atom nil))
+
+(def prompt "=> ")
+
+(defn- exit []
+  (println "\nGoodbye!")
+  (System/exit 0))
+
+(def base-ctx (merge prelude/prelude ;process/process
+                {::repl true
+                 "repl"
+                 {::data/struct true
+                  ::data/type ::data/ns
+                  ::data/name "repl"
+
+                  :flush
+                  {:name "flush"
+                   ::data/type ::data/clj
+                   :body (fn 
+                           ([]
+                            (let [session @current-session]
+                              (swap! session #(assoc % :ctx (volatile! base-ctx)))
+                              :ok))
+                           ([name]
+                            (if-let [session (get @sessions name)]
+                              (do
+                                (swap! session #(assoc % :ctx (volatile! base-ctx)))
+                                :ok)
+                              (do 
+                                (println "No session named" name)
+                                :error))))}
+
+                  :new
+                  {:name "new"
+                   ::data/type ::data/clj
+                   :body (fn [name]
+                           (let [session (new-session name)]
+                             (reset! current-session session)
+                             :ok))}
+
+                  :switch
+                  {:name "switch"
+                   ::data/type ::data/clj
+                   :body (fn [name]
+                           (if-let [session (get @sessions name)]
+                             (do
+                               (reset! current-session session)
+                               :ok)
+                             (do
+                               (println "No session named" name)
+                               :error)))}
+
+                  :quit
+                  {:name "quit"
+                   ::data/type ::data/clj
+                   :body (fn [] (exit))}
+                  }}))
+
+(defn- new-session [name]
+  (let [session (atom {:name name
+                       :ctx (volatile! base-ctx)
+                       :history []})]
+    (swap! sessions #(assoc % name session))
+    session))
+
+(defn repl-loop []
+  (let [session-atom @current-session
+        session @session-atom
+        orig-ctx (:ctx session)
+        pid (:pid session)]
+    (print (str (:name session) prompt))
+    (flush)
+    (let [input (read-line)]
+      (cond
+        (= nil input) (exit)
+
+        (= "" input) (recur)
+
+        :else
+        (let [parsed (->> input 
+                       (scanner/scan) 
+                       :tokens 
+                       (p/apply-parser g/script))]
+          (if (= :err (:status parsed))
+            (do
+              (println (p/err-msg parsed))
+              (recur))
+            (let [{result :result ctx :ctx pid- :pid}
+                  (if pid
+                    (interpreter/interpret-repl parsed orig-ctx pid)
+                    (interpreter/interpret-repl parsed orig-ctx))]
+              (if (= result :error)
+                (recur)
+                (do
+                  (println (show/show result))
+                  (when (not (= @ctx @orig-ctx))
+                    (swap! session-atom #(assoc % :ctx ctx)))
+                  (when (not (= pid pid-))
+                    (swap! session-atom #(assoc % :pid pid-)))
+                  (recur))))))))))
+
+(defn launch []
+  (println "Welcome to Ludus (v. 0.1.0-alpha)")
+  (let [session (new-session :ludus)]
+    (reset! current-session session)
+    (repl-loop)))
+