diff --git a/PythonicGcodeMachine/Gcode/Rs274/Coordinate.py b/PythonicGcodeMachine/Gcode/Rs274/Coordinate.py
new file mode 100644
index 0000000000000000000000000000000000000000..260979aa63bb1855806a0fc9658d7922c452a104
--- /dev/null
+++ b/PythonicGcodeMachine/Gcode/Rs274/Coordinate.py
@@ -0,0 +1,92 @@
+####################################################################################################
+#
+# PythonicGcodeMachine - A Python G-code Toolkit
+# Copyright (C) 2018 Fabrice Salvaire
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU 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 General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+####################################################################################################
+
+"""Module to implement a machine coordinate.
+"""
+
+####################################################################################################
+
+__all__ = [
+    'Coordinate',
+]
+
+####################################################################################################
+
+import numpy as np
+
+####################################################################################################
+
+class Coordinate:
+
+    ##############################################
+
+    def __init__(self, *args, dimension=None):
+
+        if args:
+            self._v = numpy.array(args)
+        else:
+            self._v = numpy.zeros(dimension)
+
+    ##############################################
+
+    def clone(self):
+        return self.__class__(self._v)
+
+    ##############################################
+
+    @property
+    def dimension(self):
+        return self._v.shape[0]
+
+    ##############################################
+
+    def __len__(self):
+        return self.dimension
+
+    def __iter__(self):
+        return iter(self._v)
+
+    def __getitem__(self, slice_):
+        return self._v[slice_]
+
+    ##############################################
+
+    def set(self, v):
+        if isintance(self, Coordinate):
+            self._v = self._v
+        else:
+            self._v = v
+
+    ##############################################
+
+    def __eq__(self, v):
+        return self._v == self._v
+
+    ##############################################
+
+    def __iadd__(self, v):
+        self._v += self._v
+        return self
+
+    ##############################################
+
+    def __isub__(self, v):
+        self._v -= self._v
+        return self
diff --git a/PythonicGcodeMachine/Gcode/Rs274/MachineState.py b/PythonicGcodeMachine/Gcode/Rs274/MachineState.py
new file mode 100644
index 0000000000000000000000000000000000000000..18154bbc67b8aa8d15981f494caebbbf391aed7a
--- /dev/null
+++ b/PythonicGcodeMachine/Gcode/Rs274/MachineState.py
@@ -0,0 +1,199 @@
+####################################################################################################
+#
+# PythonicGcodeMachine - A Python G-code Toolkit
+# Copyright (C) 2018 Fabrice Salvaire
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU 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 General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+####################################################################################################
+
+"""Module to implement a basic G-code machine.
+"""
+
+####################################################################################################
+
+__all__ = [
+    'MachineState',
+]
+
+####################################################################################################
+
+from enum import Enum, auto
+
+from .Coordinate import Coordinate
+from .ToolSet import ToolSet
+
+####################################################################################################
+
+class PlaneSelection:
+    XY = auto()
+    XZ = auto()
+    YZ = auto()
+
+class FeedRateMode:
+    UNITS_PER_MINUTE = auto()
+    INVERSE_TIME = auto()
+
+####################################################################################################
+
+class MachineState:
+
+    NUMBER_OF_COORDINATE_SYSTEMS = 9
+
+    ##############################################
+
+    def __init__(self,
+                 number_of_axes,
+                 is_metric=True,
+    ):
+
+        self._number_of_axes = int(number_of_axes)
+        self._coordinate = Coordinate(dimension=self._number_of_axes)
+
+        self._tool_set = ToolSet()
+        self._tool = None # T
+
+        self._is_metric = bool(is_metric)
+        self._use_metric = self._is_metric # G20 inch / G21 mm
+        self._use_absolut = True # G90 absolut / G91 incremental
+
+        # G17 XY-plane selection
+        # G18 XZ-plane selection
+        # G19 YZ-plane selection
+        self._plane = None
+
+        # G54 G55 G56 G57 G58 G59 G59.1 G59.2 G59.3
+ 	self._coordinate_system = None
+
+        self._feed_rate = 0 # F
+        # G93 units per minute
+        # G94 inverse time
+        self._feed_rate_mode = FeedRateMode.UNITS_PER_MINUTE
+
+        self._spindle_rate = 0 # S
+
+        ### 4 	M0 M1 M2 M30 M60 	stopping
+        ### 6 	M6 	tool change
+        ### 7 	M3 M4 M5 	spindle turning
+        ### 8 	M7 M8 M9 	coolant (special case: M7 and M8 may be active at the same time)
+        ### 9 	M48 M49 	enable/disable feed and speed override switches
+        ### 10 	G98 G99 	return mode in canned cycles
+        ### 13 	G61 G61.1 G64 	path control mode
+
+    ##############################################
+
+    @property
+    def number_of_axes(self):
+        return self._number_of_axes
+
+    @property
+    def coordinate(self):
+        return self._coordinate
+
+    ##############################################
+
+    @property
+    def is_metric(self):
+        return self._is_metric
+
+    @property
+    def use_metric(self):
+        return self._use_metric
+
+    @use_metric.setter
+    def use_metric(self, value):
+        self._use_metric = bool(value)
+
+    ##############################################
+
+    @property
+    def use_absolut(self):
+        return self._use_absolut
+
+    @use_absolut.setter
+    def use_absolut(self, value):
+        self._use_absolut = bool(value)
+
+    ##############################################
+
+    @property
+    def plane(self):
+        return self._plane
+
+    @plane.setter
+    def plane(self, value):
+        self._plane = PlaneSelection(value)
+
+    ##############################################
+
+    @property
+    def coordinate_system(self):
+        return self._coordinate_system
+
+    @coordinate_system.setter
+    def coordinate_system(self, value):
+        _value = int(value)
+        if not(1 <= _value <= self.NUMBER_OF_COORDINATE_SYSTEMS):
+            raise ValueError('Invalid coordinate system {}'.format(value))
+        self._coordinate_system = _value
+
+    ##############################################
+
+    @property
+    def tool_set(self):
+        return self._tool_set
+
+    def load_tool(self, pocket):
+        """Load the tool at the given carousel pocket.
+
+        Raise ValueError if KeyError.
+        """
+        self._tool.toggle_loaded()
+        try:
+            self._tool = self._tool_set[pocket].toggle_loaded()
+        except KeyError:
+            raise ValueError('Invalid carousel pocket {}'.format(pocket))
+
+    ##############################################
+
+    @property
+    def feed_rate(self):
+        return self._feed_rate
+
+    @feed_rate.setter
+    def feed_rate(self, value):
+        # negative feedback ?
+        self._feed_rate = float(value)
+
+    @property
+    def feed_rate_mode(self):
+        return self._feed_rate_mode
+
+    @feed_rate_mode.setter
+    def feed_rate_mode(self, value):
+        self._feed_rate_mode = FeedRateMode(value)
+
+    ##############################################
+
+    @property
+    def spindle_rate(self):
+        return self._spindle_rate
+
+    @spindle_rate.setter
+    def spindle_rate(self, value):
+        _value = float(value)
+        if _value < 0:
+            raise ValueError('Negative spindle rate {}'.format(value))
+        self._spindle_rate = _value
+
diff --git a/PythonicGcodeMachine/Gcode/Rs274/Tool.py b/PythonicGcodeMachine/Gcode/Rs274/Tool.py
new file mode 100644
index 0000000000000000000000000000000000000000..88aa837b19232600a278a72bcaa3f7a7fda6451d
--- /dev/null
+++ b/PythonicGcodeMachine/Gcode/Rs274/Tool.py
@@ -0,0 +1,268 @@
+####################################################################################################
+#
+# PythonicGcodeMachine - A Python G-code Toolkit
+# Copyright (C) 2018 Fabrice Salvaire
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU 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 General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+####################################################################################################
+
+"""Module to implement a basic tool set.
+"""
+
+####################################################################################################
+
+__all__ = [
+    'Tool',
+    'LatheTool',
+    'ToolSet',
+]
+
+####################################################################################################
+
+import yaml
+
+####################################################################################################
+
+class Tool:
+
+    """Class to define a tool"""
+
+    ##############################################
+
+    def __init__(self, tool_id, offset, diameter=None, comment=None):
+
+        self._id = tool_id
+        self._tool_offset = offset
+        self._tool_diameter = diameter
+        self._comment = comment
+
+        self._tool_set = None
+        self._pocket = None
+
+        self._loaded = False
+
+    ##############################################
+
+    @property
+    def id(self):
+        return self._id
+
+    @tool_id.setter
+    def id(self, value):
+        self._id = str(value)
+
+    @property
+    def offset(self):
+        return self._offset
+
+    @offset.setter
+    def offset(self, value):
+        self._offset = value
+
+    @property
+    def diameter(self):
+        return self._diameter
+
+    @diameter.setter
+    def diameter(self, value):
+        self._diameter = float(value)
+
+    @property
+    def comment(self):
+        return self._comment
+
+    @comment.setter
+    def comment(self, value):
+        self._comment = str(value)
+
+    ##############################################
+
+    @property
+    def tool_set(self):
+        return self._tool_set
+
+    @tool_set.setter
+    def tool_set(self, value):
+        self._tool_set = value
+
+    @property
+    def pocket(self):
+        return self._pocket
+
+    @pocket.setter
+    def pocket(self, value):
+        self._pocket = int(value)
+
+    ##############################################
+
+    @property
+    def loaded(self):
+        return self._loaded
+
+    @loaded.setter
+    def loaded(self, value):
+        self._loaded = bool(value)
+
+    def toggle_loaded(self):
+        self._loaded = not self._loaded
+        return self
+
+    ##############################################
+
+    def _to_dict(self, d, keys):
+        for key in keys:
+            d[key] = geattr(self, key)
+
+    ##############################################
+
+    def to_dict(self):
+
+        keys = (
+            'id',
+            'tool_offset',
+            'tool_diameter',
+            'comment',
+            'pocket',
+        )
+
+        return self._to_dict({}, keys)
+
+####################################################################################################
+
+class LatheTool(Tool):
+
+    """Class to define a lathe tool"""
+
+    ##############################################
+
+    def __init__(self, tool_id, offset, front_angle, back_angle, orientation,
+                 diameter=None, comment=None):
+
+        super(). __init__(tool_id, offset, diameter, comment)
+
+        self._front_angle = front_angle
+        self._back_angle = back_angle
+        self._orientation = orientation
+
+    ##############################################
+
+    @property
+    def front_angle(self):
+        return self._front_angle
+
+    @front_angle.setter
+    def front_angle(self, value):
+        self._front_angle = float(value)
+
+    @property
+    def back_angle(self):
+        return self._back_angle
+
+    @back_angle.setter
+    def back_angle(self, value):
+        self._back_angle = float(value)
+
+    @property
+    def orientation(self):
+        return self._orientation
+
+    @orientation.setter
+    def orientation(self, value):
+        self._orientation = int(value)
+
+    ##############################################
+
+    def to_dict(self):
+
+        d = super().to_dict()
+        keys = (
+            'front_angle',
+            'back_angle',
+            'orientation',
+        )
+        self._to_dict(d, keys)
+
+        return d
+
+####################################################################################################
+
+class ToolSet:
+
+    """Class to define a tool set"""
+
+    ##############################################
+
+    def __init__(self):
+
+        self._tools = {} # Free pocket implementation
+
+    ##############################################
+
+    def __len__(self):
+        return len(self._tools)
+
+    def __iter__(self):
+        return iter(self._tools.values())
+
+    def __getitem__(self, pocket):
+        return self._tools[pocket]
+
+    ##############################################
+
+    def remove_tool(self, pocket):
+        if isinstance(pocket, Tool):
+            pocket = pocket.pocket
+        tool = self._tools.pop(pocket)
+        tool.tool_set = None
+        tool.pocket = None
+        return tool
+
+    ##############################################
+
+    def add_tool(self, tool, pocket):
+        old_tool = self.remove_tool(pocket)
+        self._tools[pocket] = tool
+        tool.tool_set = self
+        tool.pocket = pocket
+        return old_tool
+
+    ##############################################
+
+    def load_yaml(self, path):
+
+        with (open(path, 'r')) as fh:
+            yaml_data = yaml.load(fh.read())
+
+        for pocket, d in yaml_data.items():
+            if 'front_angle' in d:
+                cls = LatheTool
+            else:
+                cls = Tool
+            tool = cls(*d)
+            self.add_tool(tool, pocket)
+
+    ##############################################
+
+    def write_yaml(self, path):
+
+        data = {}
+        for tool in self:
+            d = tool.to_dict()
+            del d['pocket']
+            data[tool.pocket] = d
+
+        yaml_data = yaml.dump(data, default_flow_style=False)
+        with (open(path, 'w')) as fh:
+            fh.write(yaml_data)
diff --git a/requirements.txt b/requirements.txt
index 6e4516b3dc77fc40edd23c647522fb412356bb1e..85b64e2fc5178850a7395fc98b73cd4919cdf9e9 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,3 +1,4 @@
 ansicolors
+numpy
 ply>=3.11
 PyYAML>=3.13