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diff --git a/src/Alpha_complex/doc/COPYRIGHT b/src/Alpha_complex/doc/COPYRIGHT
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+The files of this directory are part of the Gudhi Library - https://gudhi.inria.fr/ - which is released under MIT.
+See file LICENSE or go to https://gudhi.inria.fr/licensing/ for full license details.
+
+Author(s):       Vincent Rouvreau
+
+Copyright (C) 2015 Inria
+
+This gives everyone the freedoms to use openFrameworks in any context:
+commercial or non-commercial, public or private, open or closed source.
+
+You should have received a copy of the MIT License along with this program.
+If not, see https://opensource.org/licenses/MIT.
+\ No newline at end of file
diff --git a/src/Alpha_complex/doc/Intro_alpha_complex.h b/src/Alpha_complex/doc/Intro_alpha_complex.h
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+/*    This file is part of the Gudhi Library - https://gudhi.inria.fr/ - which is released under MIT.
+ *    See file LICENSE or go to https://gudhi.inria.fr/licensing/ for full license details.
+ *    Author(s):       Vincent Rouvreau
+ *
+ *    Copyright (C) 2015 Inria
+ *
+ *    Modification(s):
+ *      - YYYY/MM Author: Description of the modification
+ */
+
+#ifndef DOC_ALPHA_COMPLEX_INTRO_ALPHA_COMPLEX_H_
+#define DOC_ALPHA_COMPLEX_INTRO_ALPHA_COMPLEX_H_
+
+// needs namespace for Doxygen to link on classes
+namespace Gudhi {
+// needs namespace for Doxygen to link on classes
+namespace alpha_complex {
+
+/**  \defgroup alpha_complex Alpha complex
+ *
+ * \author    Vincent Rouvreau
+ *
+ * @{
+ *
+ * \section definition Definition
+ *
+ * Alpha_complex is a <a target="_blank" href="https://en.wikipedia.org/wiki/Simplicial_complex">simplicial complex</a>
+ * constructed from the finite cells of a Delaunay Triangulation.
+ *
+ * The filtration value of each simplex is computed as the square of the circumradius of the simplex if the
+ * circumsphere is empty (the simplex is then said to be Gabriel), and as the minimum of the filtration
+ * values of the codimension 1 cofaces that make it not Gabriel otherwise.
+ *
+ * All simplices that have a filtration value strictly greater than a given alpha squared value are not inserted into
+ * the complex.
+ *
+ * \image html "alpha_complex_representation.png" "Alpha-complex representation"
+ *
+ * Alpha_complex is constructing a <a target="_blank"
+ * href="http://doc.cgal.org/latest/Triangulation/index.html#Chapter_Triangulations">Delaunay Triangulation</a>
+ * \cite cgal:hdj-t-15b from <a target="_blank" href="http://www.cgal.org/">CGAL</a> (the Computational Geometry
+ * Algorithms Library \cite cgal:eb-15b) and is able to create a `SimplicialComplexForAlpha`.
+ *
+ * The complex is a template class requiring an Epick_d <a target="_blank"
+ * href="http://doc.cgal.org/latest/Kernel_d/index.html#Chapter_dD_Geometry_Kernel">dD Geometry Kernel</a>
+ * \cite cgal:s-gkd-15b from CGAL as template parameter.
+ *
+ * \remark
+ * - When the simplicial complex is constructed with an infinite value of alpha, the complex is a Delaunay
+ * complex.
+ * - For people only interested in the topology of the \ref alpha_complex (for instance persistence),
+ * \ref alpha_complex is equivalent to the \ref cech_complex and much smaller if you do not bound the radii.
+ * \ref cech_complex can still make sense in higher dimension precisely because you can bound the radii.
+ *
+ * \section pointsexample Example from points
+ *
+ * This example builds the Delaunay triangulation from the given points in a 2D static kernel, and creates a
+ * `Simplex_tree` with it.
+ *
+ * Then, it is asked to display information about the simplicial complex.
+ *
+ * \include Alpha_complex/Alpha_complex_from_points.cpp
+ *
+ * When launching:
+ *
+ * \code $> ./Alpha_complex_example_from_points
+ * \endcode
+ *
+ * the program output is:
+ *
+ * \include Alpha_complex/alphaoffreader_for_doc_60.txt
+ *
+ * \section createcomplexalgorithm Create complex algorithm
+ *
+ * \subsection datastructure Data structure
+ *
+ * In order to create the simplicial complex, first, it is built from the cells of the Delaunay Triangulation.
+ * The filtration values are set to NaN, which stands for unknown value.
+ *
+ * In example, :
+ * \image html "alpha_complex_doc.png" "Simplicial complex structure construction example"
+ *
+ * \subsection filtrationcomputation Filtration value computation algorithm
+ * <br>
+ * \f$
+ * \textbf{for } \text{i : dimension } \rightarrow 0 \textbf{ do}\\
+ * \quad \textbf{for all } \sigma \text{ of dimension i}\\
+ * \quad\quad \textbf{if } \text{filtration(} \sigma ) \text{ is NaN} \textbf{ then}\\
+ * \quad\quad\quad \text{filtration(} \sigma ) = \alpha^2( \sigma )\\
+ * \quad\quad \textbf{end if}\\
+ * \quad\quad \textbf{for all } \tau \text{ face of } \sigma \textbf{ do}\quad\quad
+ * \textit{// propagate alpha filtration value}\\
+ * \quad\quad\quad \textbf{if } \text{filtration(} \tau ) \text{ is not NaN} \textbf{ then}\\
+ * \quad\quad\quad\quad \text{filtration(} \tau \text{) = min( filtration(} \tau \text{), filtration(} \sigma
+ * \text{) )}\\
+ * \quad\quad\quad \textbf{else}\\
+ * \quad\quad\quad\quad \textbf{if } \tau \text{ is not Gabriel for } \sigma \textbf{ then}\\
+ * \quad\quad\quad\quad\quad \text{filtration(} \tau \text{) = filtration(} \sigma \text{)}\\
+ * \quad\quad\quad\quad \textbf{end if}\\
+ * \quad\quad\quad \textbf{end if}\\
+ * \quad\quad \textbf{end for}\\
+ * \quad \textbf{end for}\\
+ * \textbf{end for}\\
+ * \text{make_filtration_non_decreasing()}\\
+ * \text{prune_above_filtration()}\\
+ * \f$
+ *
+ * \subsubsection dimension2 Dimension 2
+ *
+ * From the example above, it means the algorithm looks into each triangle ([0,1,2], [0,2,4], [1,2,3], ...),
+ * computes the filtration value of the triangle, and then propagates the filtration value as described
+ * here :
+ * \image html "alpha_complex_doc_420.png" "Filtration value propagation example"
+ *
+ * \subsubsection dimension1 Dimension 1
+ *
+ * Then, the algorithm looks into each edge ([0,1], [0,2], [1,2], ...),
+ * computes the filtration value of the edge (in this case, propagation will have no effect).
+ *
+ * \subsubsection dimension0 Dimension 0
+ *
+ * Finally, the algorithm looks into each vertex ([0], [1], [2], [3], [4], [5] and [6]) and
+ * sets the filtration value (0 in case of a vertex - propagation will have no effect).
+ *
+ * \subsubsection nondecreasing Non decreasing filtration values
+ *
+ * As the squared radii computed by CGAL are an approximation, it might happen that these alpha squared values do not
+ * quite define a proper filtration (i.e. non-decreasing with respect to inclusion).
+ * We fix that up by calling `SimplicialComplexForAlpha::make_filtration_non_decreasing()`.
+ *
+ * \subsubsection pruneabove Prune above given filtration value
+ *
+ * The simplex tree is pruned from the given maximum alpha squared value (cf.
+ * `SimplicialComplexForAlpha::prune_above_filtration()`).
+ * In the following example, the value is given by the user as argument of the program.
+ *
+ *
+ * \section offexample Example from OFF file
+ *
+ * This example builds the Delaunay triangulation in a dynamic kernel, and initializes the alpha complex with it.
+ *
+ *
+ * Then, it is asked to display information about the alpha complex.
+ *
+ * \include Alpha_complex/Alpha_complex_from_off.cpp
+ *
+ * When launching:
+ *
+ * \code $> ./Alpha_complex_example_from_off ../../data/points/alphacomplexdoc.off 32.0
+ * \endcode
+ *
+ * the program output is:
+ *
+ * \include Alpha_complex/alphaoffreader_for_doc_32.txt
+ *
+ *
+ * \section weighted3dexample 3d specific example
+ *
+ * A specific module for Alpha complex is available in 3d (cf. Alpha_complex_3d) and allows to construct standard,
+ * weighted, periodic or weighted and periodic versions of alpha complexes. Alpha values computation can be
+ * Gudhi::alpha_complex::complexity::FAST, Gudhi::alpha_complex::complexity::SAFE (default value) or
+ * Gudhi::alpha_complex::complexity::EXACT.
+ *
+ * This example builds the CGAL 3d weighted alpha shapes from a small molecule, and initializes the alpha complex with
+ * it. This example is taken from <a href="https://doc.cgal.org/latest/Alpha_shapes_3/index.html#title13">CGAL 3d
+ * weighted alpha shapes</a>.
+ *
+ * Then, it is asked to display information about the alpha complex.
+ *
+ * \include Alpha_complex/Weighted_alpha_complex_3d_from_points.cpp
+ *
+ * When launching:
+ *
+ * \code $> ./Alpha_complex_example_weighted_3d_from_points
+ * \endcode
+ *
+ * the program output is:
+ *
+ * \include Alpha_complex/weightedalpha3dfrompoints_for_doc.txt
+ *
+ */
+/** @} */  // end defgroup alpha_complex
+
+}  // namespace alpha_complex
+
+namespace alphacomplex = alpha_complex;
+
+}  // namespace Gudhi
+
+#endif  // DOC_ALPHA_COMPLEX_INTRO_ALPHA_COMPLEX_H_
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