diff --git a/Makefile b/Makefile
index 18f51cb..de22701 100644
--- a/Makefile
+++ b/Makefile
@@ -15,144 +15,60 @@ BINDIR=bin
 BUILDDIR=build
 SRCDIR=src
 
-sources = $(shell find . -maxdepth 1 -type f -name "*.c")
-objects = $(patsubst %.c,%.o,$(sources))
-dependencies = $(patsubst %.c,%.d,$(sources))
+SOURCES = $(shell find $(SRCDIR) -type f -name "*.c")
+OBJECTS = $(patsubst %.c,$(BUILDDIR)/%.o,$(SOURCES))
+DEPENDENCIES = $(patsubst %.c,$(BUILDDIR)/%.d,$(SOURCES))
 
-all: myprogram
+all: $(BINDIR)/gem-graph-client
 
--include $(dependencies)
+-include /etc/os-release
 
-myprogram: $(objects)
-	$(CC) $(LDFLAGS) $(WARNINGS) $(DEBUG) $(OPTIMIZE) $^ -o $@
+#
+# Directories
+#
+$(BUILDDIR):
+	mkdir -p $@
 
-%.o: %.c Makefile
-	$(CC) $(CFLAGS) $(WARNINGS) $(DEBUG) $(OPTIMIZE) -c $< -o $@
+$(BINDIR):
+	mkdir -p $@
 
-%.d: %.c Makefile
+#
+# Dependencies
+#
+-include $(DEPENDENCIES)
+
+$(BUILDDIR)/%.d: %.c Makefile | $(BUILDDIR)
+	mkdir -p $(shell dirname $@)
 	$(CC) $(CFLAGS) -MM -MT $(@:%.d=%.o) -MF $@ $<
 
+#
+# Main program
+#
+$(BINDIR)/gem-graph-client: $(OBJECTS) | $(BINDIR)
+	$(CC) $(LDFLAGS) $(WARNINGS) $(DEBUG) $(OPTIMIZE) $^ -o $@
+
+#
+# Objects
+#
+$(BUILDDIR)/%.o: %.c Makefile | $(BUILDDIR)
+	mkdir -p $(shell dirname $@)
+	$(CC) $(CFLAGS) $(WARNINGS) $(DEBUG) $(OPTIMIZE) -c $< -o $@
+
+#
+# Virtual recipes
+#
 install:
 	echo "Installing is not supported"
 
-run: myprogram
-	./myprogram
+run: $(BINDIR)/gem-graph-client
+	$(BINDIR)/gem-graph-client
 
 clean:
-	rm -f myprogram
-	rm -f *.o
-	rm -f *.d
-
-# /!\  erreur fatale: GL/glu.h   <?>
-#  gcc -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -g -Wall -Wextra
-# -std=c99 -lm *.c -o formattage `pkg-config --cflags --libs glib-2.0`
-
-#------------------------------------------------------------------------------#
-#	    'make' has an implicit rule for updating a ‘.o’ file               #
-#		    from a correspondingly named ‘.c’ file                     #
-#		            using a ‘cc -c’ command.                           #
-#  Implicit rules are listed and applied in a predefined order (C before P...) #
-#       Predefined implicit rules are implemented in make as suffix rules      #
-#    The default suffix list is: .out, .a, .ln, .o, .c, .cc, .C, .cpp, .p,...  #
-#	     Rules whose suffixes fail to be on the list are disabled.         #
-#        You can define your own implicit rules by writing pattern rules.      #
-#------------------------------------------------------------------------------#
-
-# If there are many implicit rules with the same target pattern,
-# the rule that actually applies is the one whose prerequisites exist or can be made
-# ex: a .o can be made from a .c (C compiler) or a .p (Pascal compiler)
-
-#	Variables allow a text string to be defined once
-#	    and substituted in multiple places later.
-#	(see Chapter 6 [How to Use Variables], page 65)
+	rm -rf $(BINDIR)
+	rm -rf $(BUILDDIR)
 
 
-
-#------------------------------------------------------------------------------#
-#           To study : how can the following commands be modified ?            #
-#------------------------------------------------------------------------------#
-
-#SHELL = /bin/sh
-#.SUFFIXES:
-#.SUFFIXES: .c .o .h       # is  .h  useful ?
-#.PHONY = run
-#.PHONY = clean
-#.PHONY: Makefile
-
-#CC=gcc
-#CFLAGS=`pkg-config --cflags gtk4 --libs gtk4`
-#WARNINGS = -Wall
-#DEBUG = -ggdb -fno-omit-frame-pointer
-#OPTIMIZE = -O2
-
-# in exec.o:
-#	$(WARNINGS) $(DEBUG) $(OPTIMIZE)   <   ne sont pas indispensables
-#	si le $@ est supprimé, main.cest modifié
-#all:
-#	exec
-
-#install:
-#	echo "Installing is not supported"
-
-
-
-
-
-
-#------------------------------------------------------------------------------#
-#                        Personnal notes & links                               #
-#------------------------------------------------------------------------------#
-
-
-# gcc $( pkg-config --cflags gtk4 ) -o exec main.c $( pkg-config --libs gtk4 )
-
+# More docs :
 #       https://www.gnu.org/software/make/manual/
-
-#	Makefiles contain five kinds of things:
-#	explicit rules, implicit rules, variable definitions, directives and comments.
-
-
-#    Variables automatiques   --------------------------------------------------
-#    $@    fait référence à la cible de la règle (au nom de la cible).
-#    $<    fait référence à la première dépendance.
-#    $?    fait référence aux noms de touess les dépendances plus récentes que la cible.
-#	   = les fichiers qui ont été modifiés après la compilation de code la plus récente
-#    $^    fait référence aux noms de touess les dépendances avec des espaces entre eux.
-
-#	Variables implicites   -------------------------------------------------
-#	VPATH   Équivalent utilitaire de la variable PATH de Bash. Vide par défaut.
-#		Les chemins sont séparés par le signe deux-points (:).
-#	CC      Le programme pour compiler des fichiers C.
-#		La valeur par défaut est cc. (Habituellement, cc pointe vers gcc.)
-#	CPP     Le programme qui exécute le préprocesseur C.
-#		La valeur par défaut est $ (CC) -E.
-#	LEX     Le programme qui transforme les grammaires lexicales en code source.
-#		La valeur par défaut est lex. (Vous devriez remplacer cela par flex.)
-#	LINT    Le programme qui lint votre code source. La valeur par défaut est lint.
-#	RM      La commande pour supprimer un fichier. La valeur par défaut est rm -f.
-#	CFLAGS	Contient tous les indicateurs du compilateur C (cc).
-#	CPPFLAGS	 tous les indicateurs du préprocesseur C.
-#	.PHONY  Spécifie des cibles qui ne ressemblent pas au nom d'un fichier.
-#		Un exemple est la cible "make clean" ; où clean est une valeur de .PHONY
-
-#	Syntaxe de Base
-#	Règles : Une règle se compose d'une cible, des dépendances et des commandes.
-#		 Elle est généralement structurée comme suit :
-#		 cible: dépendances
-#		        commande
-#
-#	La cible (target) est le fichier à générer,
-#	les dépendances (prerequisites) sont les fichiers requis pour construire la cible
-#	et les commandes (recipe) sont les instructions exécutées pour créer la cible.
-#
-#	A simple makefile consists of “rules” with the following shape:
-#		target ... : 	prerequisites ...
-#				recipe
-#				...
-#	A target is usually the name of a file that is generated by a program;
-#		examples of targets are executable or object files.
-#	A target can also be the name of an action to carry out, such as ‘clean’
-
-
 #	accessoirement : https://blog.stephane-robert.info/docs/makefile/  & /docs/task/
 
diff --git a/dimers random walk.xml b/data/dimers random walk.xml
similarity index 100%
rename from dimers random walk.xml
rename to data/dimers random walk.xml
diff --git a/automaton.h b/include/automaton.h
similarity index 100%
rename from automaton.h
rename to include/automaton.h
diff --git a/base.h b/include/base.h
similarity index 100%
rename from base.h
rename to include/base.h
diff --git a/callback.h b/include/callback.h
similarity index 100%
rename from callback.h
rename to include/callback.h
diff --git a/contain.h b/include/contain.h
similarity index 100%
rename from contain.h
rename to include/contain.h
diff --git a/dialog.h b/include/dialog.h
similarity index 100%
rename from dialog.h
rename to include/dialog.h
diff --git a/display.h b/include/display.h
similarity index 100%
rename from display.h
rename to include/display.h
diff --git a/graph_area.h b/include/graph_area.h
similarity index 100%
rename from graph_area.h
rename to include/graph_area.h
diff --git a/graphics.h b/include/graphics.h
similarity index 100%
rename from graphics.h
rename to include/graphics.h
diff --git a/parsing.h b/include/parsing.h
similarity index 100%
rename from parsing.h
rename to include/parsing.h
diff --git a/texts.h b/include/texts.h
similarity index 100%
rename from texts.h
rename to include/texts.h
diff --git a/tree.h b/include/tree.h
similarity index 100%
rename from tree.h
rename to include/tree.h
diff --git a/init.c.todo b/init.c.todo
deleted file mode 100644
index 7789ec0..0000000
--- a/init.c.todo
+++ /dev/null
@@ -1,175 +0,0 @@
-/*
- *      Gem-graph OpenGL experiments
- *
- *      Desc: GL functions
- *
- *  Copyright (C) 2023 Arthur Menges <arthur.menges@a-lec.org>
- *  Copyright (C) 2023 Adrien Bourmault <neox@a-lec.org>
- *
- *  This file is part of Gem-graph.
- *
- *  This program is free software: you can redistribute it and/or modify
- *  it under the terms of the GNU Affero General Public License as published by
- *  the Free Software Foundation, either version 3 of the License, or
- *  (at your option) any later version.
- *
- *  This program 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 Affero General Public License for more details.
- *
- *  You should have received a copy of the GNU Affero General Public License
- *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-/* -------------------------------------------------------------------------- */
-
-#include <stdlib.h>
-#include <time.h>
-#include "base.h"
-#include "contain.h" // instead of "ui.h"
-#include "graph_area.h"
-
-/* Initializes the buffer of a gl_area
- * Calls according to the user preferences
- * @param   gl_area, ptr to the gl_area widget
- * @return  void
- */
-void graphics_init_buffers(const int stack_id)
-{
-    struct graphic_stack_t *stack = &graphic_stack[stack_id];
-
-    //XXX
-    graphics_model_setup(stack_id);
-
-    GLuint vao, vertex_buffer, color_buffer;
-
-    glGenBuffers(1, &vertex_buffer);
-    glBindBuffer(GL_ARRAY_BUFFER, vertex_buffer);
-    glBufferData(GL_ARRAY_BUFFER,
-                 stack->buffer_vertex_size *
-                    sizeof(stack->buffer_vertex_origin[0]),
-                 stack->buffer_vertex_origin,
-                 GL_STATIC_DRAW);
-    glBindBuffer(GL_ARRAY_BUFFER, 0);
-
-
-    // colors
-    glGenBuffers(1, &color_buffer);
-    glBindBuffer(GL_ARRAY_BUFFER, color_buffer);
-    glBufferData(GL_ARRAY_BUFFER, stack->buffer_colors_size *
-                    sizeof(stack->buffer_colors_origin[0]),
-                 stack->buffer_colors_origin,
-                 GL_STATIC_DRAW);
-    glBindBuffer(GL_ARRAY_BUFFER, 0);
-
-    // We only use one VAO, so we always keep it bound
-    glGenVertexArrays(1, &vao);
-    glBindVertexArray(vao);
-
-    stack->vao = vao;
-    stack->position_buffer = vertex_buffer;
-    stack->color_buffer = color_buffer;
-}
-
-/*
- * Initializes the shaders of a gl_area and link them to a program
- *
- * @param   gl_area, ptr to the gl_area widget
- *
- * @return  true if initialized
- */
-bool graphics_init_shaders(const int stack_id)
-{
-    struct graphic_stack_t *stack = &graphic_stack[stack_id];
-    char *vertex_shader;
-    char *fragment_shader;
-    int status;
-    GLuint vertex = 0, fragment;  //  2024-06-05   j'initialise vertex à 0 (au pif !)
-    GLuint program = 0;
-    GLuint m = 0;
-    GLuint v = 0;
-    GLuint p = 0;
-
-    // Load vertex shader file
-    vertex_shader = read_file(VERTEX_SHADER_FILE);
-    if (vertex_shader == NULL)
-        return false;
-    vertex = create_shader(stack_id, GL_VERTEX_SHADER, vertex_shader);
-
-    if(vertex == 0) {
-        stack->program = 0;
-        g_free(vertex_shader);
-        return false;
-    }
-
-    // Load fragment shader file
-    fragment_shader = read_file(FRAG_SHADER_FILE);
-    if (fragment_shader == NULL)
-        return false;
-    fragment = create_shader(stack_id, GL_FRAGMENT_SHADER, fragment_shader);
-
-    if(fragment == 0) {
-        glDeleteShader(vertex);
-        stack->program = 0;
-        g_free(vertex_shader);
-        g_free(fragment_shader);
-        return false;
-    }
-
-    // Link shaders to program
-    program = glCreateProgram();
-    glAttachShader(program, vertex);
-    glAttachShader(program, fragment);
-
-    glLinkProgram(program);
-
-    glGetProgramiv(program, GL_LINK_STATUS, &status);
-
-    if(status == GL_FALSE) {
-        int log_len;
-        char *buffer;
-
-        glGetProgramiv(program, GL_INFO_LOG_LENGTH, &log_len);
-
-        buffer = g_malloc(log_len + 1);
-        assert(buffer);
-        glGetProgramInfoLog(program, log_len, NULL, buffer);
-
-        g_warning("Linking failure:\n%s", buffer);
-
-        g_free(buffer);
-
-        glDeleteProgram(program);
-        program = 0;
-
-        glDeleteShader(vertex);
-        glDeleteShader(fragment);
-
-        g_free(vertex_shader);
-        g_free(fragment_shader);
-
-        return false;
-    }
-
-    /* Get the location of the "mvp" uniform */
-    m = glGetUniformLocation(program, "model_matrix");
-    v = glGetUniformLocation(program, "view_matrix");
-    p = glGetUniformLocation(program, "projection_matrix");
-
-    glDetachShader(program, vertex);
-    glDetachShader(program, fragment);
-
-    glDeleteShader(vertex);
-    glDeleteShader(fragment);
-
-    stack->program = program;
-    stack->m = m;
-    stack->v = v;
-    stack->p = p;
-
-    g_free(vertex_shader);
-    g_free(fragment_shader);
-
-    return true;
-}
diff --git a/automaton.c b/src/automaton.c
similarity index 98%
rename from automaton.c
rename to src/automaton.c
index 4f4f6fa..6e431df 100644
--- a/automaton.c
+++ b/src/automaton.c
@@ -1,6 +1,6 @@
 #include <gtk-4.0/gtk/gtk.h>
 #include <assert.h>
-#include "callback.h"
+#include "../include/callback.h"
 #include "automaton.h"
 
 
diff --git a/callback.c b/src/callback.c
similarity index 100%
rename from callback.c
rename to src/callback.c
diff --git a/contain.c b/src/contain.c
similarity index 100%
rename from contain.c
rename to src/contain.c
diff --git a/dialog.c b/src/dialog.c
similarity index 100%
rename from dialog.c
rename to src/dialog.c
diff --git a/display.c b/src/display.c
similarity index 100%
rename from display.c
rename to src/display.c
diff --git a/draw.c b/src/draw.c
similarity index 100%
rename from draw.c
rename to src/draw.c
diff --git a/graph_area.c b/src/graph_area.c
similarity index 100%
rename from graph_area.c
rename to src/graph_area.c
diff --git a/graph_stack.c b/src/graph_stack.c
similarity index 100%
rename from graph_stack.c
rename to src/graph_stack.c
diff --git a/grid.c b/src/grid.c
similarity index 100%
rename from grid.c
rename to src/grid.c
diff --git a/init.c b/src/init.c
similarity index 100%
rename from init.c
rename to src/init.c
diff --git a/src/main.c b/src/main.c
new file mode 100644
index 0000000..a5f9b0c
--- /dev/null
+++ b/src/main.c
@@ -0,0 +1,26 @@
+/******************************************************************************/
+/*                                                                            */
+/*                     E coli by David S. Goodsell (2009)                     */
+/*                                   ---                                      */
+/*               Let this freeze frame guide us towards the model             */
+/*                  that alone can account for the phenomenon !               */
+/*                                                                            */
+/******************************************************************************/
+
+#include "callback.h"
+
+int main (int argc, char **argv)
+{
+  GtkApplication *app;
+  int status;
+
+  app = gtk_application_new ("org.jean.GTK4_GG_hack", G_APPLICATION_DEFAULT_FLAGS);
+  g_signal_connect (app, "activate", G_CALLBACK (on_main_window_activation), NULL);
+  g_signal_connect (app, "activate", G_CALLBACK (on_dialog_window_activation), NULL);
+  status = g_application_run (G_APPLICATION (app), argc, argv);
+  g_object_unref (app);
+
+  printf("in contain.get_SPACE_VIEW_box()  (line 138)   >   ui_setup_glarea (0, GTK_WIDGET (middle_box));   <   commented  2024/06/27   >   TODO\n");
+
+  return status;
+}
diff --git a/parsing.c b/src/parsing.c
similarity index 100%
rename from parsing.c
rename to src/parsing.c
diff --git a/shader.frag b/src/shader.frag
similarity index 100%
rename from shader.frag
rename to src/shader.frag
diff --git a/shader.vert b/src/shader.vert
similarity index 100%
rename from shader.vert
rename to src/shader.vert
diff --git a/texts.c b/src/texts.c
similarity index 100%
rename from texts.c
rename to src/texts.c
diff --git a/tree.c b/src/tree.c
similarity index 100%
rename from tree.c
rename to src/tree.c