diff --git a/java/src/org/broadinstitute/sting/playground/gatk/walkers/concordance/NWayVenn.java b/java/src/org/broadinstitute/sting/playground/gatk/walkers/concordance/NWayVenn.java
new file mode 100755
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--- /dev/null
+++ b/java/src/org/broadinstitute/sting/playground/gatk/walkers/concordance/NWayVenn.java
@@ -0,0 +1,116 @@
+package org.broadinstitute.sting.playground.gatk.walkers.concordance;
+
+import org.broadinstitute.sting.gatk.contexts.ReferenceContext;
+import org.broadinstitute.sting.gatk.refdata.RefMetaDataTracker;
+import org.broadinstitute.sting.gatk.refdata.ReferenceOrderedDatum;
+import org.broadinstitute.sting.gatk.refdata.RODRecordList;
+import org.broadinstitute.sting.utils.StingException;
+import org.broadinstitute.sting.utils.Utils;
+import org.broadinstitute.sting.utils.genotype.Variation;
+
+import java.io.FileNotFoundException;
+import java.io.PrintWriter;
+import java.util.HashMap;
+import java.util.Map.Entry;
+
+/**
+ * Split up N call sets into their various "Venn diagram" sets.
+ * Note that to minimize complexity (unlike SimpleVenn), this module does NOT check for discordance
+ * (i.e. the intersections contain calls that are present in multiple sets, regardless of whether
+ * they agree on the actual variant).
+ */
+public class NWayVenn implements ConcordanceType {
+
+    // TODO -- change this to use Ryan's generic map object when it's ready
+    private HashMap<Integer, PrintWriter> writers = new HashMap<Integer, PrintWriter>();
+
+    private String prefix;
+    private int N;
+
+    private PrintWriter union_writer = null;
+
+    public NWayVenn() {}
+
+    public void initialize(String prefix, HashMap<String,String> args) {
+
+        if ( args.get("N") == null )
+            throw new StingException("NWayVenn concordance module requires the 'N' argument");
+        N = Integer.valueOf(args.get("N"));
+        if ( N < 1 )
+            throw new StingException("NWayVenn concordance module requires that N be greater than 0");
+
+        this.prefix = prefix;
+
+        // create the list of file names
+        HashMap<String, String> files = new HashMap<String, String>();
+        files.put("", "");
+        for (int i = 1; i <= N; i++) {
+            // create 2 new list entries for each of the current file names:
+            // one with and one without this set appended to the end
+            HashMap<String, String> appendedFiles = new HashMap<String, String>();            
+            for ( Entry<String, String> file : files.entrySet() ) {
+                appendedFiles.put(file.getKey() + "0", file.getValue());
+                appendedFiles.put(file.getKey() + "1", file.getValue() + ".set" + i);
+            }
+            files = appendedFiles;
+        }
+        // remove the entry for no hits
+        files.remove(Utils.dupString('0', N));
+
+        try {
+            for ( Entry<String, String> file : files.entrySet() )
+                writers.put(stringToHash(file.getKey()), new PrintWriter(prefix + "." + N + "wayVenn" + file.getValue() + ".calls"));
+            union_writer = new PrintWriter(prefix + "." + N + "wayVenn.union.calls");
+        } catch (FileNotFoundException e) {
+            throw new StingException(String.format("Could not open file(s) for writing"));
+        }
+    }
+
+    public void computeConcordance(RefMetaDataTracker tracker, ReferenceContext ref) {
+        Variation[] calls = new Variation[N];
+        int goodRods = 0;
+        for (int i = 0; i < N; i++) {
+            RODRecordList<ReferenceOrderedDatum> callList = tracker.getTrackData("callset" + (i+1), null);
+            if ( callList != null ) {
+                calls[i] = (Variation)callList.getRecords().get(0);
+                goodRods++;
+            }
+        }
+
+        if ( goodRods == 0 )
+            return;
+
+        // union
+        printVariant(union_writer, calls);
+
+        // add to the correct set
+        StringBuilder hashString = new StringBuilder();
+        for (int i = 0; i < N; i++)
+            hashString.append(calls[i] != null ? "1" : "0");
+        printVariant(writers.get(stringToHash(hashString.toString())), calls);
+    }
+
+    private static void printVariant(PrintWriter writer, Variation[] variants) {
+        for ( Variation variant : variants ) {
+            if ( variant != null ) {
+                writer.println(variant.toString());
+                return;
+            }
+        }
+    }
+
+    public void cleanup() {
+        union_writer.close();
+        for ( PrintWriter writer : writers.values() )
+            writer.close();
+    }
+
+    private int stringToHash(String s) {
+        int hash = 0;
+        for (int i = 0; i < s.length(); i++) {
+            if ( s.charAt(i) == '1' )
+                hash += Math.pow(2, i);
+        }
+        return hash;
+    }
+}
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