diff --git a/Hungarian-Munkres.cabal b/Hungarian-Munkres.cabal
new file mode 100644
--- /dev/null
+++ b/Hungarian-Munkres.cabal
@@ -0,0 +1,47 @@
+-- Initial hungarian.cabal generated by cabal init.  For further 
+-- documentation, see http://haskell.org/cabal/users-guide/
+
+name:                Hungarian-Munkres
+version:             0.1.0
+synopsis:            A linear Sum Assignment Problme (LSAP) solver
+description:         This library provide a Haskell binding to the libhungarian,
+                     a solver for Linear Sum Assignment Problem (LSAP) implemented
+                     in C language. It uses Hungarian algorithm 
+                     <http://en.wikipedia.org/wiki/Hungarian_algorithm>, and runs 
+                     in O(n^3) time.
+license:             GPL-3
+license-file:        LICENSE
+author:              Kai Zhang <kai@kzhang.org>
+maintainer:          Kai Zhang <kai@kzhang.org>
+copyright:           Kai Zhang
+category:            Algorithm
+build-type:          Simple
+-- extra-source-files:  
+cabal-version:       >=1.10
+
+library
+  exposed-modules:     Algorithms.Hungarian
+  -- other-modules:       
+  -- other-extensions:    
+  build-depends:       base >=4.7 && <4.8
+  hs-source-dirs:      src
+  c-sources:           cbits/hungarian.c
+  default-language:    Haskell2010
+
+test-suite             tests
+  type:                exitcode-stdio-1.0
+  hs-source-dirs:      tests
+  main-is:             tests.hs
+  default-language:    Haskell2010
+  build-depends:
+      base >=4.7 && <4.8
+    , array
+    , Hungarian-Munkres
+    , Munkres
+    , tasty
+    , tasty-quickcheck
+    , random
+
+source-repository  head
+  type: git
+  location: https://github.com/kaizhang/hungarian-munkres.git
diff --git a/LICENSE b/LICENSE
new file mode 100644
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,674 @@
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+
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+may consider it more useful to permit linking proprietary applications with
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diff --git a/Setup.hs b/Setup.hs
new file mode 100644
--- /dev/null
+++ b/Setup.hs
@@ -0,0 +1,2 @@
+import Distribution.Simple
+main = defaultMain
diff --git a/cbits/hungarian.c b/cbits/hungarian.c
new file mode 100644
--- /dev/null
+++ b/cbits/hungarian.c
@@ -0,0 +1,402 @@
+/********************************************************************
+ ********************************************************************
+ **
+ ** libhungarian by Cyrill Stachniss, 2004
+ **
+ **
+ ** Solving the Minimum Assignment Problem using the 
+ ** Hungarian Method.
+ **
+ ** ** This file may be freely copied and distributed! **
+ **
+ ** Parts of the used code was originally provided by the 
+ ** "Stanford GraphGase", but I made changes to this code.
+ ** As asked by  the copyright node of the "Stanford GraphGase", 
+ ** I hereby proclaim that this file are *NOT* part of the
+ ** "Stanford GraphGase" distrubition!
+ **
+ ** This file is distributed in the hope that it will be useful,
+ ** but WITHOUT ANY WARRANTY; without even the implied 
+ ** warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+ ** PURPOSE.  
+ **
+ ********************************************************************
+ ********************************************************************/
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include "hungarian.h"
+
+#define INF (1.0/0.0)
+#define verbose (0)
+
+#define hungarian_test_alloc(X) do {if ((void *)(X) == NULL) fprintf(stderr, "Out of memory in %s, (%s, line %d).\n", __FUNCTION__, __FILE__, __LINE__); } while (0)
+
+int hungarian(double* data, int* result, int rows, int cols) {
+  int i,j;
+  hungarian_problem_t p;
+  int matrix_size = hungarian_init(&p, data , rows, cols, HUNGARIAN_MODE_MINIMIZE_COST) ;
+  hungarian_solve(&p);
+
+  for(i=0;i<rows;i++)
+      for(j=0;j<cols;j++)
+          result[i*cols+j] = p.assignment[i][j];
+
+  hungarian_free(&p);
+
+  return 0;
+}
+
+
+int hungarian_imax(int a, int b) {
+  return (a<b)?b:a;
+}
+
+int hungarian_init(hungarian_problem_t* p, double* cost_matrix, int rows, int cols, int mode) {
+
+  int i,j, org_cols, org_rows;
+  double max_cost;
+  max_cost = 0;
+  
+  org_cols = cols;
+  org_rows = rows;
+
+  // is the number of cols  not equal to number of rows ? 
+  // if yes, expand with 0-cols / 0-cols
+  rows = hungarian_imax(cols, rows);
+  cols = rows;
+  
+  p->num_rows = rows;
+  p->num_cols = cols;
+
+  p->cost = (double**)calloc(rows,sizeof(double*));
+  hungarian_test_alloc(p->cost);
+  p->assignment = (int**)calloc(rows,sizeof(int*));
+  hungarian_test_alloc(p->assignment);
+
+  for(i=0; i<p->num_rows; i++) {
+    p->cost[i] = (double*)calloc(cols,sizeof(double));
+    hungarian_test_alloc(p->cost[i]);
+    p->assignment[i] = (int*)calloc(cols,sizeof(int));
+    hungarian_test_alloc(p->assignment[i]);
+    for(j=0; j<p->num_cols; j++) {
+      p->cost[i][j] =  (i < org_rows && j < org_cols) ? cost_matrix[i*org_cols+j] : 0;
+      p->assignment[i][j] = 0;
+
+      if (max_cost < p->cost[i][j])
+        max_cost = p->cost[i][j];
+    }
+  }
+
+
+  if (mode == HUNGARIAN_MODE_MAXIMIZE_UTIL) {
+    for(i=0; i<p->num_rows; i++) {
+      for(j=0; j<p->num_cols; j++) {
+	p->cost[i][j] =  max_cost - p->cost[i][j];
+      }
+    }
+  }
+  else if (mode == HUNGARIAN_MODE_MINIMIZE_COST) {
+    // nothing to do
+  }
+  else 
+    fprintf(stderr,"%s: unknown mode. Mode was set to HUNGARIAN_MODE_MINIMIZE_COST !\n", __FUNCTION__);
+  
+  return rows;
+}
+
+
+void hungarian_free(hungarian_problem_t* p) {
+  int i;
+  for(i=0; i<p->num_rows; i++) {
+    free(p->cost[i]);
+    free(p->assignment[i]);
+  }
+  free(p->cost);
+  free(p->assignment);
+  p->cost = NULL;
+  p->assignment = NULL;
+}
+
+
+
+double hungarian_solve(hungarian_problem_t* p)
+{
+  int i, j, m, n, k, l, t, q, unmatched;
+  double s, cost;
+  int* col_mate;
+  int* row_mate;
+  int* parent_row;
+  int* unchosen_row;
+  double* row_dec;
+  double* col_inc;
+  double* slack;
+  int* slack_row;
+
+  cost=0;
+  m =p->num_rows;
+  n =p->num_cols;
+
+  col_mate = (int*)calloc(p->num_rows,sizeof(int));
+  hungarian_test_alloc(col_mate);
+  unchosen_row = (int*)calloc(p->num_rows,sizeof(int));
+  hungarian_test_alloc(unchosen_row);
+  row_dec  = (double*)calloc(p->num_rows,sizeof(double));
+  hungarian_test_alloc(row_dec);
+  slack_row  = (int*)calloc(p->num_rows,sizeof(int));
+  hungarian_test_alloc(slack_row);
+
+  row_mate = (int*)calloc(p->num_cols,sizeof(int));
+  hungarian_test_alloc(row_mate);
+  parent_row = (int*)calloc(p->num_cols,sizeof(int));
+  hungarian_test_alloc(parent_row);
+  col_inc = (double*)calloc(p->num_cols,sizeof(double));
+  hungarian_test_alloc(col_inc);
+  slack = (double*)calloc(p->num_cols,sizeof(double));
+  hungarian_test_alloc(slack);
+
+  for (i=0;i<p->num_rows;i++) {
+    col_mate[i]=0;
+    unchosen_row[i]=0;
+    row_dec[i]=0;
+    slack_row[i]=0;
+  }
+  for (j=0;j<p->num_cols;j++) {
+    row_mate[j]=0;
+    parent_row[j] = 0;
+    col_inc[j]=0;
+    slack[j]=0;
+  }
+
+  for (i=0;i<p->num_rows;++i)
+    for (j=0;j<p->num_cols;++j)
+      p->assignment[i][j]=HUNGARIAN_NOT_ASSIGNED;
+
+  // Begin subtract column minima in order to start with lots of zeroes 12
+  if (verbose)
+    fprintf(stderr, "Using heuristic\n");
+  for (l=0;l<n;l++) {
+    s=p->cost[0][l];
+    for (k=1;k<m;k++) 
+      if (p->cost[k][l]<s)
+        s=p->cost[k][l];
+    cost+=s;
+    if (s!=0)
+      for (k=0;k<m;k++)
+        p->cost[k][l]-=s;
+  }
+  // End subtract column minima in order to start with lots of zeroes 12
+
+  // Begin initial state 16
+  t=0;
+  for (l=0;l<n;l++)
+    {
+      row_mate[l]= -1;
+      parent_row[l]= -1;
+      col_inc[l]=0;
+      slack[l]=INF;
+    }
+  for (k=0;k<m;k++)
+    {
+      s=p->cost[k][0];
+      for (l=1;l<n;l++)
+	if (p->cost[k][l]<s)
+	  s=p->cost[k][l];
+      row_dec[k]=s;
+      for (l=0;l<n;l++)
+	if (s==p->cost[k][l] && row_mate[l]<0)
+	  {
+	    col_mate[k]=l;
+	    row_mate[l]=k;
+	    if (verbose)
+	      fprintf(stderr, "matching col %d==row %d\n",l,k);
+	    goto row_done;
+	  }
+      col_mate[k]= -1;
+      if (verbose)
+	fprintf(stderr, "node %d: unmatched row %d\n",t,k);
+      unchosen_row[t++]=k;
+    row_done:
+      ;
+    }
+  // End initial state 16
+ 
+  // Begin Hungarian algorithm 18
+  if (t==0)
+    goto done;
+  unmatched=t;
+  while (1)
+    {
+      if (verbose)
+	fprintf(stderr, "Matched %d rows.\n",m-t);
+      q=0;
+      while (1)
+	{
+	  while (q<t)
+	    {
+	      // Begin explore node q of the forest 19
+	      {
+		k=unchosen_row[q];
+		s=row_dec[k];
+		for (l=0;l<n;l++)
+		  if (slack[l])
+		    {
+		      double del;
+		      del=p->cost[k][l]-s+col_inc[l];
+		      if (del<slack[l])
+			{
+			  if (del==0)
+			    {
+			      if (row_mate[l]<0)
+				goto breakthru;
+			      slack[l]=0;
+			      parent_row[l]=k;
+			      if (verbose)
+				fprintf(stderr, "node %d: row %d==col %d--row %d\n",
+				       t,row_mate[l],l,k);
+			      unchosen_row[t++]=row_mate[l];
+			    }
+			  else
+			    {
+			      slack[l]=del;
+			      slack_row[l]=k;
+			    }
+			}
+		    }
+	      }
+	      // End explore node q of the forest 19
+	      q++;
+	    }
+ 
+	  // Begin introduce a new zero into the matrix 21
+	  s=INF;
+	  for (l=0;l<n;l++)
+	    if (slack[l] && slack[l]<s)
+	      s=slack[l];
+	  for (q=0;q<t;q++)
+	    row_dec[unchosen_row[q]]+=s;
+	  for (l=0;l<n;l++)
+	    if (slack[l])
+	      {
+		slack[l]-=s;
+		if (slack[l]==0)
+		  {
+		    // Begin look at a new zero 22
+		    k=slack_row[l];
+		    if (verbose)
+		      fprintf(stderr, 
+			     "Decreasing uncovered elements by %f produces zero at [%d,%d]\n",
+			     s,k,l);
+		    if (row_mate[l]<0)
+		      {
+			for (j=l+1;j<n;j++)
+			  if (slack[j]==0)
+			    col_inc[j]+=s;
+			goto breakthru;
+		      }
+		    else
+		      {
+			parent_row[l]=k;
+			if (verbose)
+			  fprintf(stderr, "node %d: row %d==col %d--row %d\n",t,row_mate[l],l,k);
+			unchosen_row[t++]=row_mate[l];
+		      }
+		    // End look at a new zero 22
+		  }
+	      }
+	    else
+	      col_inc[l]+=s;
+	  // End introduce a new zero into the matrix 21
+	}
+    breakthru:
+      // Begin update the matching 20
+      if (verbose)
+	fprintf(stderr, "Breakthrough at node %d of %d!\n",q,t);
+      while (1)
+	{
+	  j=col_mate[k];
+	  col_mate[k]=l;
+	  row_mate[l]=k;
+	  if (verbose)
+	    fprintf(stderr, "rematching col %d==row %d\n",l,k);
+	  if (j<0)
+	    break;
+	  k=parent_row[j];
+	  l=j;
+	}
+  // End update the matching 20
+  if (--unmatched==0) 
+    goto done;
+      // Begin get ready for another stage 17
+      t=0;
+      for (l=0;l<n;l++)
+	{
+	  parent_row[l]= -1;
+	  slack[l]=INF;
+	}
+      for (k=0;k<m;k++)
+	if (col_mate[k]<0)
+	  {
+	    if (verbose)
+	      fprintf(stderr, "node %d: unmatched row %d\n",t,k);
+	    unchosen_row[t++]=k;
+	  }
+      // End get ready for another stage 17
+    }
+ done:
+
+  /*
+  // Begin doublecheck the solution 23
+  for (k=0;k<m;k++)
+    for (l=0;l<n;l++)
+      if (p->cost[k][l]<row_dec[k]-col_inc[l])
+	exit(0);
+  for (k=0;k<m;k++)
+    {
+      l=col_mate[k];
+      if (l<0 || p->cost[k][l]!=row_dec[k]-col_inc[l])
+	exit(0);
+    }
+  k=0;
+  for (l=0;l<n;l++)
+    if (col_inc[l])
+      k++;
+  if (k>m)
+    exit(0);
+  // End doublecheck the solution 23
+  // End Hungarian algorithm 18
+  // */
+
+  for (i=0;i<m;++i)
+    {
+      p->assignment[i][col_mate[i]]=HUNGARIAN_ASSIGNED;
+      //TRACE("%d - %d\n", i, col_mate[i]);
+    }
+  for (k=0;k<m;++k)
+    {
+      for (l=0;l<n;++l)
+	{
+	  //TRACE("%d ",p->cost[k][l]-row_dec[k]+col_inc[l]);
+	  p->cost[k][l]=p->cost[k][l]-row_dec[k]+col_inc[l];
+	}
+      //TRACE("\n");
+    }
+  for (i=0;i<m;i++)
+    cost+=row_dec[i];
+  for (i=0;i<n;i++)
+    cost-=col_inc[i];
+  if (verbose)
+    fprintf(stderr, "Cost is %f\n",cost);
+
+
+  free(slack);
+  free(col_inc);
+  free(parent_row);
+  free(row_mate);
+  free(slack_row);
+  free(row_dec);
+  free(unchosen_row);
+  free(col_mate);
+  return cost;
+}
diff --git a/src/Algorithms/Hungarian.hs b/src/Algorithms/Hungarian.hs
new file mode 100644
--- /dev/null
+++ b/src/Algorithms/Hungarian.hs
@@ -0,0 +1,38 @@
+{-# LANGUAGE ForeignFunctionInterface #-}
+
+module Algorithms.Hungarian 
+    ( hungarian
+    , hungarianScore
+    ) where
+
+import Data.List
+import Foreign.Ptr
+import Foreign.C
+import Foreign.Marshal.Array
+import System.IO.Unsafe
+
+foreign import ccall "hungarian"
+    c_hungarian :: Ptr CDouble -> Ptr CInt -> CInt -> CInt -> IO Double
+
+-- | solve the LSAP by hungarian algorithm, return assignment and score
+hungarian :: [Double]               -- ^ row majored flat matrix
+          -> Int                    -- ^ number of rows
+          -> Int                    -- ^ number of columns
+          -> ([(Int, Int)], Double)
+hungarian costMatrix nrows ncols = unsafePerformIO $ do
+    withArray (map realToFrac costMatrix) $ \input -> 
+        allocaArray (nrows * ncols) $ \output -> do
+            cost <- c_hungarian input output (fromIntegral nrows) (fromIntegral ncols)
+            results <- peekArray (nrows * ncols) output
+            return (getAssign results, realToFrac cost)
+  where
+    getAssign :: [CInt] -> [(Int, Int)]
+    getAssign = snd . foldl' step (0,[])
+    step (i,assign) x | x == 0 = (i+1, assign)
+                      | otherwise = (i+1, (i `div` ncols, i `mod` ncols) : assign)
+{-# INLINE hungarian #-}
+
+-- | solve the LSAP by hungarian algorithm, return score only
+hungarianScore :: [Double] -> Int -> Int -> Double
+hungarianScore costMatrix nrows = snd . hungarian costMatrix nrows
+{-# INLINE hungarianScore #-}
diff --git a/tests/tests.hs b/tests/tests.hs
new file mode 100644
--- /dev/null
+++ b/tests/tests.hs
@@ -0,0 +1,25 @@
+import Algorithms.Hungarian
+import Data.Algorithm.Munkres
+import Data.Array.Unboxed
+import Test.Tasty
+import Test.Tasty.QuickCheck
+import System.Random
+
+main :: IO ()
+main = defaultMain $ testGroup "Hungarian-Munkres"
+    [ testProperty "Hungarian" (\x -> uncurry (~=) $ t_hungarian x)
+    ]
+
+t_hungarian :: Int -> (Double, Double)
+t_hungarian g = (hungarianScore xs rows cols, solution)
+  where
+    solution = snd $ hungarianMethodDouble $ listArray ((1,1), (rows, cols)) xs
+    (xs, rows, cols) = randMat (mkStdGen g)
+
+randMat :: StdGen -> ([Double], Int, Int)
+randMat g = (take (rows * cols) $ randoms g, rows, cols)
+  where
+    [rows, cols] = take 2 $ randomRs (100, 150) g
+
+(~=) :: Double -> Double -> Bool
+(~=) a b = abs (a - b) < 1e-12
