diff --git a/core/pom.xml b/core/pom.xml
index 1317659..6ce49f3 100644
--- a/core/pom.xml
+++ b/core/pom.xml
@@ -34,6 +34,48 @@
         <includes><include>LICENSE</include></includes>
       </resource>
     </resources>
+
+    <plugins>
+      <plugin>
+        <groupId>org.codehaus.mojo</groupId>
+        <artifactId>build-helper-maven-plugin</artifactId>
+        <version>1.5</version>
+        <executions>
+          <execution>
+            <id>add-test-source</id>
+            <phase>process-resources</phase>
+            <goals>
+              <goal>add-test-source</goal>
+            </goals>
+            <configuration>
+              <sources>
+                <source>src/it/java</source>
+              </sources>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
+
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-failsafe-plugin</artifactId>
+        <version>2.15</version>
+        <executions>
+          <execution>
+            <id>integration-test</id>
+            <goals>
+              <goal>integration-test</goal>
+            </goals>
+          </execution>
+          <execution>
+            <id>verify</id>
+            <goals>
+              <goal>verify</goal>
+            </goals>
+          </execution>
+        </executions>
+      </plugin>
+    </plugins>
   </build>
 
 </project>
diff --git a/core/src/it/java/com/threerings/getdown/tests/DigesterTest.java b/core/src/it/java/com/threerings/getdown/tests/DigesterTest.java
new file mode 100644
index 0000000..342a0d6
--- /dev/null
+++ b/core/src/it/java/com/threerings/getdown/tests/DigesterTest.java
@@ -0,0 +1,53 @@
+//
+// Getdown - application installer, patcher and launcher
+// Copyright (C) 2004-2016 Getdown authors
+// https://github.com/threerings/getdown/blob/master/LICENSE
+
+package com.threerings.getdown.tests;
+
+import java.io.File;
+import java.nio.file.*;
+import java.util.Arrays;
+import java.util.List;
+
+import org.junit.*;
+import static org.junit.Assert.*;
+
+import com.threerings.getdown.tools.Digester;
+
+public class DigesterTest {
+
+    @Test
+    public void testDigester () throws Exception {
+        Path appdir = Paths.get("src/it/resources/testapp");
+        Digester.createDigests(appdir.toFile(), null, null, null);
+
+        Path digest = appdir.resolve("digest.txt");
+        List<String> digestLines = Files.readAllLines(digest);
+        Files.delete(digest);
+
+        Path digest2 = appdir.resolve("digest2.txt");
+        List<String> digest2Lines = Files.readAllLines(digest2);
+        Files.delete(digest2);
+
+        assertEquals(Arrays.asList(
+            "getdown.txt = 779c74fb4b251e18faf6e240a0667964",
+            "testapp.jar = 404dafa55e78b25ec0e3a936357b1883",
+            "funny%test dir/some=file.txt = d8e8fca2dc0f896fd7cb4cb0031ba249",
+            "crazyhashfile#txt = f29d23fd5ab1781bd8d0760b3a516f16",
+            "foo.jar = 46ca4cc9079d9d019bb30cd21ebbc1ec",
+            "script.sh = f66e8ea25598e67e99c47d9b0b2a2cdf",
+            "digest.txt = f5561d85e4d80cc85883963897e58ff6"
+        ), digestLines);
+
+        assertEquals(Arrays.asList(
+            "getdown.txt = 4f0c657895c3c3a35fa55bf5951c64fa9b0694f8fc685af3f1d8635c639e066b",
+            "testapp.jar = c9cb1906afbf48f8654b416c3f831046bd3752a76137e5bf0a9af2f790bf48e0",
+            "funny%test dir/some=file.txt = f2ca1bb6c7e907d06dafe4687e579fce76b37e4e93b7605022da52e6ccc26fd2",
+            "crazyhashfile#txt = 6816889f922de38f145db215a28ad7c5e1badf7354b5cdab225a27486789fa3b",
+            "foo.jar = ea188b872e0496debcbe00aaadccccb12a8aa9b025bb62c130cd3d9b8540b062",
+            "script.sh = cca1c5c7628d9bf7533f655a9cfa6573d64afb8375f81960d1d832dc5135c988",
+            "digest2.txt = 70b442c9f56660561921da3368e1a206f05c379182fab3062750b7ddcf303407"
+        ), digest2Lines);
+    }
+}
diff --git a/core/src/it/resources/testapp/background.png b/core/src/it/resources/testapp/background.png
new file mode 100644
index 0000000..ff6a6ee
Binary files /dev/null and b/core/src/it/resources/testapp/background.png differ
diff --git a/core/src/it/resources/testapp/crazyhashfile#txt b/core/src/it/resources/testapp/crazyhashfile#txt
new file mode 100644
index 0000000..33bc373
--- /dev/null
+++ b/core/src/it/resources/testapp/crazyhashfile#txt
@@ -0,0 +1 @@
+Hello crazy world.
diff --git a/core/src/it/resources/testapp/foo.jar b/core/src/it/resources/testapp/foo.jar
new file mode 100644
index 0000000..d040c01
Binary files /dev/null and b/core/src/it/resources/testapp/foo.jar differ
diff --git a/core/src/it/resources/testapp/funny%test dir/some=file.txt b/core/src/it/resources/testapp/funny%test dir/some=file.txt
new file mode 100644
index 0000000..9daeafb
--- /dev/null
+++ b/core/src/it/resources/testapp/funny%test dir/some=file.txt	
@@ -0,0 +1 @@
+test
diff --git a/core/src/it/resources/testapp/getdown.txt b/core/src/it/resources/testapp/getdown.txt
new file mode 100644
index 0000000..3e0e538
--- /dev/null
+++ b/core/src/it/resources/testapp/getdown.txt
@@ -0,0 +1,28 @@
+# where our app is hosted on the internets
+appbase = http://notused.com/testapp
+
+# the jar file that contains our code
+code = testapp.jar
+
+# the main entry point of our app
+class = com.threerings.testapp.TestApp
+
+# we pass the appdir to our app so that it can upgrade getdown
+apparg = %APPDIR%
+
+# test the %env% mechanism
+jvmarg = -Dusername=\%ENV.USER%
+
+strict_comments = true
+resource = funny%test dir/some=file.txt
+resource = crazyhashfile#txt
+uresource = foo.jar
+xresource = script.sh
+
+ui.name = Getdown Test App
+ui.background_image = background.png
+ui.progress = 17, 321, 458, 22
+ui.progress_bar = 336600
+ui.progress_text = FFFFFF
+ui.status = 57, 245, 373, 68
+ui.status_text = 000000
diff --git a/core/src/it/resources/testapp/script.sh b/core/src/it/resources/testapp/script.sh
new file mode 100644
index 0000000..e3a1aba
--- /dev/null
+++ b/core/src/it/resources/testapp/script.sh
@@ -0,0 +1,3 @@
+#!/bin/sh
+
+echo "Hello world!"
diff --git a/core/src/it/resources/testapp/testapp.jar b/core/src/it/resources/testapp/testapp.jar
new file mode 100644
index 0000000..fe9de02
Binary files /dev/null and b/core/src/it/resources/testapp/testapp.jar differ