diff --git a/eo/src/es/eoSBXcross.h b/eo/src/es/eoSBXcross.h
new file mode 100644
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--- /dev/null
+++ b/eo/src/es/eoSBXcross.h
@@ -0,0 +1,116 @@
+// -*- mode: c++; c-indent-level: 4; c++-member-init-indent: 8; comment-column: 35; -*-
+
+//-----------------------------------------------------------------------------
+// eoSBXcross.h
+// (c) Maarten Keijzer 2000 - Marc Schoenauer 2001
+/* 
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Lesser General Public
+    License as published by the Free Software Foundation; either
+    version 2 of the License, or (at your option) any later version.
+
+    This library 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.  See the GNU
+    Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public
+    License along with this library; if not, write to the Free Software
+    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+    Contact: Marc.Schoenauer@polytechnique.fr
+             mak@dhi.dk
+ */
+//-----------------------------------------------------------------------------
+
+#include <algorithm>    // swap_ranges
+#include <utils/eoRNG.h>
+#include <es/eoReal.h>
+#include <utils/eoRealBounds.h>
+#include <utils/eoRealVectorBounds.h>
+
+
+
+template<class EOT> class eoSBXCrossover: public eoQuadOp<EOT>
+{
+ public:
+  /****
+   * (Default) Constructor.
+   * The bounds are initialized with the global object that says: no bounds.
+   *
+   * 
+   */
+    eoSBXCrossover(const double& _eta = 1.0) :
+    bounds(eoDummyVectorNoBounds), eta(_eta), range(1) {}
+
+
+  //////////////////////////////////////////////
+
+  /**
+   * Constructor with bounds
+   * @param _bounds an eoRealVectorBounds that contains the bounds
+   * @param _alphaMin the amount of exploration OUTSIDE the parents 
+   *               as in BLX-alpha notation (Eshelman and Schaffer)
+   *               0 == contractive application
+   *               Must be positive
+   */
+
+
+
+     eoSBXCrossover(eoRealVectorBounds & _bounds, 
+   		     const double& _eta = 1.0) : 
+     bounds(_bounds), eta(_eta), range(1) {}
+
+  ///////////////////////////////////////////////
+
+
+  /// The class name.
+  virtual string className() const { return "eoSBXCrossover"; }
+
+  /*****************************************
+   * SBX crossover - modifies both parents *
+   * @param _eo1 The first parent          *
+   * @param _eo2 The first parent          *    
+   *****************************************/
+  bool operator()(EOT& _eo1, EOT& _eo2)
+    {
+      unsigned i;
+      double r1, r2, beta;
+
+	for (i=0; i<_eo1.size(); i++)
+	  {
+      double u = rng.uniform(range) ;
+
+      if ( u <= 0.5 ) 
+	beta = exp( (1/(eta+1))*log(2*u));
+      else
+	beta = exp((1/(eta+1))*log(1/(2*(1-u))));
+
+
+	    
+	      r1=_eo1[i];
+	      r2=_eo2[i];   
+	      _eo1[i] =0.5*((1+beta)*r1+(1-beta)*r2);
+	      _eo2[i] =0.5*((1-beta)*r1+(1+beta)*r2);
+
+	
+	      if(!(bounds.isInBounds(i,_eo1[i])))
+		bounds.foldsInBounds(i,_eo1[i]);
+	      if(!(bounds.isInBounds(i,_eo2[i])))
+		bounds.foldsInBounds(i,_eo2[i]);
+
+
+
+	   }
+	return true;
+	}
+                  	   
+    
+
+protected:
+  eoRealVectorBounds & bounds;
+  double eta;
+  double range;			   // == 1
+};
+
+