diff --git a/SimPEG/Model.py b/SimPEG/Model.py
index f6d4d6d4..ce2349d0 100644
--- a/SimPEG/Model.py
+++ b/SimPEG/Model.py
@@ -64,6 +64,68 @@ class BaseModel(object):
             m = self.example()
         return checkDerivative(lambda m : [self.transform(m), self.transformDeriv(m)], m, plotIt=False)
 
+class BaseNonLinearModel(object):
+    """
+    SimPEG BaseNonLinearModel
+
+    """
+
+    __metaclass__ = Utils.SimPEGMetaClass
+
+    counter = None   #: A SimPEG.Utils.Counter object
+    mesh = None      #: A SimPEG Mesh
+
+    def __init__(self, mesh):
+        self.mesh = mesh
+
+    def transform(self, u, m):
+        """
+            :param numpy.array u: fields
+            :param numpy.array m: model
+            :rtype: numpy.array
+            :return: transformed model
+
+            The *transform* changes the model into the physical property.
+
+        """
+        return m
+
+    def transformDerivU(self, u, m):
+        """
+            :param numpy.array u: fields
+            :param numpy.array m: model
+            :rtype: scipy.csr_matrix
+            :return: derivative of transformed model
+
+            The *transform* changes the model into the physical property.
+            The *transformDerivU* provides the derivative of the *transform* with respect to the fields.
+        """
+        raise NotImplementedError('The transformDerivU is not implemented.')
+
+
+    def transformDerivM(self, u, m):
+        """
+            :param numpy.array u: fields
+            :param numpy.array m: model
+            :rtype: scipy.csr_matrix
+            :return: derivative of transformed model
+
+            The *transform* changes the model into the physical property.
+            The *transformDerivU* provides the derivative of the *transform* with respect to the model.
+        """
+        raise NotImplementedError('The transformDerivM is not implemented.')
+
+    @property
+    def nP(self):
+        """Number of parameters in the model."""
+        return self.mesh.nC
+
+    def example(self):
+        raise NotImplementedError('The example is not implemented.')
+
+    def test(self, m=None):
+        raise NotImplementedError('The test is not implemented.')
+
 
 class LogModel(BaseModel):
     """SimPEG LogModel"""
diff --git a/SimPEG/Problem.py b/SimPEG/Problem.py
index 350ff93a..414d0c33 100644
--- a/SimPEG/Problem.py
+++ b/SimPEG/Problem.py
@@ -41,7 +41,7 @@ class BaseProblem(object):
     dataPair = Data.BaseData
     modelPair = Model.BaseModel
 
-    def __init__(self, mesh, model, *args, **kwargs):
+    def __init__(self, mesh, model, **kwargs):
         Utils.setKwargs(self, **kwargs)
         self.mesh = mesh
         assert isinstance(model, self.modelPair), "Model object must be an instance of a %s class."%(self.modelPair.__name__)
diff --git a/docs/api_BaseMesh.rst b/docs/api_BaseMesh.rst
deleted file mode 100644
index fcf0e8c1..00000000
--- a/docs/api_BaseMesh.rst
+++ /dev/null
@@ -1,8 +0,0 @@
-.. _api_BaseMesh:
-
-Base Mesh
-*********
-
-.. automodule:: SimPEG.Mesh.BaseMesh
-    :members:
-    :undoc-members:
diff --git a/docs/api_Cyl1DMesh.rst b/docs/api_Cyl1DMesh.rst
deleted file mode 100644
index 573e6c5e..00000000
--- a/docs/api_Cyl1DMesh.rst
+++ /dev/null
@@ -1,8 +0,0 @@
-.. _api_Cyl1DMesh:
-
-Cylindrical 1D Mesh
-*******************
-
-.. automodule:: SimPEG.Mesh.Cyl1DMesh
-    :members:
-    :undoc-members:
diff --git a/docs/api_DiffOperators.rst b/docs/api_DiffOperators.rst
deleted file mode 100644
index a3a2ca98..00000000
--- a/docs/api_DiffOperators.rst
+++ /dev/null
@@ -1,8 +0,0 @@
-.. _api_DiffOperators:
-
-Differential Operators
-**********************
-
-.. automodule:: SimPEG.Mesh.DiffOperators
-    :members:
-    :undoc-members:
diff --git a/docs/api_Forward.rst b/docs/api_Forward.rst
index 91009294..067a902f 100644
--- a/docs/api_Forward.rst
+++ b/docs/api_Forward.rst
@@ -2,7 +2,7 @@
 
 
 Model
-*****
+=====
 
 .. automodule:: SimPEG.Model
     :show-inheritance:
@@ -11,7 +11,7 @@ Model
     :inherited-members:
 
 Data
-****
+====
 
 .. automodule:: SimPEG.Data
     :show-inheritance:
@@ -20,7 +20,7 @@ Data
     :inherited-members:
 
 Problem
-*******
+=======
 
 .. automodule:: SimPEG.Problem
     :show-inheritance:
diff --git a/docs/api_InnerProducts.rst b/docs/api_InnerProducts.rst
deleted file mode 100644
index e2f54c8e..00000000
--- a/docs/api_InnerProducts.rst
+++ /dev/null
@@ -1,8 +0,0 @@
-.. _api_InnerProducts:
-
-Inner Products
-**************
-
-.. automodule:: SimPEG.Mesh.InnerProducts
-    :members:
-    :undoc-members:
diff --git a/docs/api_Inverse.rst b/docs/api_Inverse.rst
index 21f4386e..ab711f81 100644
--- a/docs/api_Inverse.rst
+++ b/docs/api_Inverse.rst
@@ -2,7 +2,7 @@
 
 
 Regularization
-**************
+==============
 
 .. automodule:: SimPEG.Regularization
     :show-inheritance:
@@ -11,7 +11,7 @@ Regularization
 
 
 Objective Function
-******************
+==================
 
 .. automodule:: SimPEG.ObjFunction
     :members:
@@ -19,7 +19,7 @@ Objective Function
 
 
 Optimize
-********
+========
 
 .. automodule:: SimPEG.Optimization
     :show-inheritance:
@@ -28,7 +28,7 @@ Optimize
     :undoc-members:
 
 Inversion
-*********
+=========
 
 .. automodule:: SimPEG.Inversion
     :show-inheritance:
diff --git a/docs/api_LogicallyOrthogonalMesh.rst b/docs/api_LogicallyOrthogonalMesh.rst
deleted file mode 100644
index 449ed6f8..00000000
--- a/docs/api_LogicallyOrthogonalMesh.rst
+++ /dev/null
@@ -1,10 +0,0 @@
-.. _api_LogicallyOrthogonalMesh:
-
-Logically Orthogonal Mesh
-*************************
-
-.. automodule:: SimPEG.Mesh.LogicallyOrthogonalMesh
-    :show-inheritance:
-    :members:
-    :undoc-members:
-    :inherited-members:
diff --git a/docs/api_Mesh.rst b/docs/api_Mesh.rst
new file mode 100644
index 00000000..a964b24d
--- /dev/null
+++ b/docs/api_Mesh.rst
@@ -0,0 +1,53 @@
+.. _api_Mesh:
+
+
+Tensor Mesh
+===========
+
+.. automodule:: SimPEG.Mesh.TensorMesh
+    :show-inheritance:
+    :members:
+    :undoc-members:
+    :inherited-members:
+
+
+Cylindrical 1D Mesh
+===================
+
+.. automodule:: SimPEG.Mesh.Cyl1DMesh
+    :members:
+    :undoc-members:
+
+
+Logically Orthogonal Mesh
+=========================
+
+.. automodule:: SimPEG.Mesh.LogicallyOrthogonalMesh
+    :show-inheritance:
+    :members:
+    :undoc-members:
+    :inherited-members:
+
+
+
+Base Mesh
+=========
+
+.. automodule:: SimPEG.Mesh.BaseMesh
+    :members:
+    :undoc-members:
+
+
+Inner Products
+==============
+
+.. automodule:: SimPEG.Mesh.InnerProducts
+    :members:
+    :undoc-members:
+
+Differential Operators
+======================
+
+.. automodule:: SimPEG.Mesh.DiffOperators
+    :members:
+    :undoc-members:
diff --git a/docs/api_Parameters.rst b/docs/api_Parameters.rst
index e90b58a5..1a333b88 100644
--- a/docs/api_Parameters.rst
+++ b/docs/api_Parameters.rst
@@ -2,7 +2,7 @@
 
 
 Parameters
-**********
+==========
 
 .. automodule:: SimPEG.Parameters
     :show-inheritance:
diff --git a/docs/api_TensorMesh.rst b/docs/api_TensorMesh.rst
deleted file mode 100644
index 9cf80c41..00000000
--- a/docs/api_TensorMesh.rst
+++ /dev/null
@@ -1,10 +0,0 @@
-.. _api_TensorMesh:
-
-Tensor Mesh
-***********
-
-.. automodule:: SimPEG.Mesh.TensorMesh
-    :show-inheritance:
-    :members:
-    :undoc-members:
-    :inherited-members:
diff --git a/docs/api_Tests.rst b/docs/api_Tests.rst
index 0ab45c51..614d8747 100644
--- a/docs/api_Tests.rst
+++ b/docs/api_Tests.rst
@@ -1,7 +1,7 @@
 .. _api_Tests:
 
 Testing SimPEG
-**************
+==============
 
 .. automodule:: SimPEG.Tests.TestUtils
     :members:
diff --git a/docs/api_Utils.rst b/docs/api_Utils.rst
index 9c40cabe..641e6d60 100644
--- a/docs/api_Utils.rst
+++ b/docs/api_Utils.rst
@@ -17,42 +17,35 @@ Utilities
     :undoc-members:
 
 Matrix Utilities
-****************
+================
 
 .. automodule:: SimPEG.Utils.matutils
     :members:
     :undoc-members:
 
-Sparse Utilities
-****************
-
-.. automodule:: SimPEG.Utils.sputils
-    :members:
-    :undoc-members:
-
 LOM Utilities
-*************
+=============
 
 .. automodule:: SimPEG.Utils.lomutils
     :members:
     :undoc-members:
 
 Mesh Utilities
-**************
+==============
 
 .. automodule:: SimPEG.Utils.meshutils
     :members:
     :undoc-members:
 
 Model Builder Utilities
-***********************
+=======================
 
 .. automodule:: SimPEG.Utils.ModelBuilder
     :members:
     :undoc-members:
 
 Interpolation Utilities
-***********************
+=======================
 
 .. automodule:: SimPEG.Utils.interputils
     :members:
diff --git a/docs/index.rst b/docs/index.rst
index 9ed98291..84e0f925 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -11,10 +11,12 @@ The vision is to create a package for finite volume simulation and parameter est
 applications to geophysical imaging and subsurface flow. To enable
 these goals, this package has the following features:
 
-* is modular with respect to discretization, physics, optimization, and regularization
-* is built with the (large-scale) inverse problem in mind
-* provides a framework for geophysical and hydrogeologic problems
-* supports 1D, 2D and 3D problems
+
+   * is modular with respect to discretization, physics, optimization, and regularization
+   * is built with the (large-scale) inverse problem in mind
+   * provides a framework for geophysical and hydrogeologic problems
+   * supports 1D, 2D and 3D problems
+
 
 .. image:: simpeg-framework.png
    :width: 400 px
@@ -22,20 +24,15 @@ these goals, this package has the following features:
    :align: center
 
 Meshing & Operators
-===================
+*******************
 
 .. toctree::
    :maxdepth: 2
 
-   api_BaseMesh
-   api_TensorMesh
-   api_LogicallyOrthogonalMesh
-   api_Cyl1DMesh
-   api_DiffOperators
-   api_InnerProducts
+   api_Mesh
 
 Forward Problems
-================
+****************
 
 .. toctree::
    :maxdepth: 2
@@ -43,7 +40,7 @@ Forward Problems
    api_Forward
 
 Inversion
-=========
+*********
 
 .. toctree::
    :maxdepth: 2
@@ -52,7 +49,7 @@ Inversion
    api_Parameters
 
 Testing SimPEG
-==============
+**************
 
 .. toctree::
    :maxdepth: 2
@@ -60,20 +57,20 @@ Testing SimPEG
    api_Tests
 
 * Master Branch
-   .. image:: https://travis-ci.org/simpeg/simpeg.png?branch=master
+   .. image:: https://travis-ci.org/simpeg/simpeg.png?branch*master
       :target: https://travis-ci.org/simpeg/simpeg
       :alt: Master Branch
       :align: center
 
 * Develop Branch
-   .. image:: https://travis-ci.org/simpeg/simpeg.png?branch=develop
+   .. image:: https://travis-ci.org/simpeg/simpeg.png?branch*develop
       :target: https://travis-ci.org/simpeg/simpeg
       :alt: Develop Branch
       :align: center
 
 
 Utility Codes
-=============
+*************
 
 .. toctree::
    :maxdepth: 2
@@ -82,7 +79,7 @@ Utility Codes
 
 
 Project Index & Search
-======================
+**********************
 
 * :ref:`genindex`
 * :ref:`modindex`