diff --git a/README.md b/README.md
new file mode 100644
index 0000000..ffe8a8f
--- /dev/null
+++ b/README.md
@@ -0,0 +1,36 @@
+rdfdiff
+=======
+
+Compute human readable diffs between RDF graphs.
+
+Use Jena to check two RDF graphs to see if they are isomorphic, and if
+not, show which statements are only in one graph and not in the other.
+From the Jena docs:
+
+     Two models are isomorphic when each statement in one can be
+     matched with a statement in the other. Statements which are
+     identical match.
+
+     Special treatment is given to anonymous nodes. A binding is a one
+     to one mapping which maps each anonymous node in this model to an
+     anonymous node in model. Two statements s1 and s2 match under a
+     binding if if s1.subject is anonymous and s2.subject is anonymous
+     and the binding maps s1.subject to s2.subject.
+
+     Two models are isomorphic if there is a binding that allows all
+     the statements in one model to match a a statement in the other.
+
+Building and using
+------------------
+
+The build uses sbt, the Scala Build Tool.  Once sbt is installed,
+build the utility using:
+
+    sbt assembly
+
+resulting in target/scala-2.12/rdfdiff, an executable JAR file with
+all necessary Jena libraries included.  Copy the file to somewhere in
+your path, e.g. /usr/local/bin/ and make it executable.
+
+--
+Alex Tucker, 2018.
diff --git a/build.sbt b/build.sbt
index 2d226f6..c2ea52d 100644
--- a/build.sbt
+++ b/build.sbt
@@ -9,3 +9,4 @@
   "com.github.scopt" %% "scopt" % "3.7.0"
 )
 
+assemblyJarName in assembly := "rdfdiff.jar"