diff --git a/kite/config.py b/kite/config.py
new file mode 100644
index 0000000..cd7cfd9
--- /dev/null
+++ b/kite/config.py
@@ -0,0 +1,159 @@
+# http://pyrocko.org - GPLv3
+#
+# The Pyrocko Developers, 21st Century
+# ---|P------/S----------~Lg----------
+from __future__ import absolute_import
+import os
+import os.path as op
+from copy import deepcopy
+
+from pyrocko import util
+from pyrocko.guts import Object, Float, String, load, dump, TBase, Int
+
+guts_prefix = 'pf'
+
+kite_dir_tmpl = os.environ.get(
+    'KITE_DIR',
+    os.path.join('~', '.kite'))
+
+
+def make_conf_path_tmpl(name='config'):
+    return op.join(kite_dir_tmpl, '%s.pf' % name)
+
+
+default_phase_key_mapping = {
+    'F1': 'P', 'F2': 'S', 'F3': 'R', 'F4': 'Q', 'F5': '?'}
+
+
+class BadConfig(Exception):
+    pass
+
+
+class PathWithPlaceholders(String):
+    '''Path, possibly containing placeholders.'''
+    pass
+
+
+class VisibleLengthSetting(Object):
+    class __T(TBase):
+        def regularize_extra(self, val):
+            if isinstance(val, list):
+                return self.cls(key=val[0], value=val[1])
+
+            return val
+
+        def to_save(self, val):
+            return (val.key, val.value)
+
+        def to_save_xml(self, val):
+            raise NotImplementedError()
+
+    key = String.T()
+    value = Float.T()
+
+
+class ConfigBase(Object):
+    @classmethod
+    def default(cls):
+        return cls()
+
+
+class KiteConfig(ConfigBase):
+
+    quadtree_min_tile_factor = Int.T(
+        default=6,
+        help='Exponent to the basis of 2. '
+             'The larger the smaller the potential quadtree.')
+    epsilon_min_factor = Float.T(
+        default=0.1,
+        help='The smaller the smaller the potential epsilon min')
+
+
+config_cls = {
+    'config': KiteConfig,
+}
+
+
+def fill_template(tmpl, config_type):
+    tmpl = tmpl .format(
+        module=('.' + config_type) if config_type != 'kite' else '')
+    return tmpl
+
+
+def expand(x):
+    x = op.expanduser(op.expandvars(x))
+    return x
+
+
+def rec_expand(x):
+    for prop, val in x.T.ipropvals(x):
+        if prop.multivalued:
+            if val is not None:
+                for i, ele in enumerate(val):
+                    if isinstance(prop.content_t, PathWithPlaceholders.T):
+                        newele = expand(ele)
+                        if newele != ele:
+                            val[i] = newele
+
+                    elif isinstance(ele, Object):
+                        rec_expand(ele)
+        else:
+            if isinstance(prop, PathWithPlaceholders.T):
+                newval = expand(val)
+                if newval != val:
+                    setattr(x, prop.name, newval)
+
+            elif isinstance(val, Object):
+                rec_expand(val)
+
+
+def processed(config):
+    config = deepcopy(config)
+    rec_expand(config)
+    return config
+
+
+def mtime(p):
+    return os.stat(p).st_mtime
+
+
+g_conf_mtime = {}
+g_conf = {}
+
+
+def raw_config(config_name='config'):
+
+    conf_path = expand(make_conf_path_tmpl(config_name))
+
+    if not op.exists(conf_path):
+        g_conf[config_name] = config_cls[config_name].default()
+        write_config(g_conf[config_name], config_name)
+
+    conf_mtime_now = mtime(conf_path)
+    if conf_mtime_now != g_conf_mtime.get(config_name, None):
+        g_conf[config_name] = load(filename=conf_path)
+        if not isinstance(g_conf[config_name], config_cls[config_name]):
+            raise BadConfig('config file does not contain a '
+                            'valid "%s" section.' %
+                            config_cls[config_name].__name__)
+
+        g_conf_mtime[config_name] = conf_mtime_now
+
+    return g_conf[config_name]
+
+
+def config(config_name='config'):
+    return processed(raw_config(config_name))
+
+
+def write_config(conf, config_name='config'):
+    conf_path = expand(make_conf_path_tmpl(config_name))
+    util.ensuredirs(conf_path)
+    dump(conf, filename=conf_path)
+
+
+override_gui_toolkit = None
+
+
+def effective_gui_toolkit():
+    return override_gui_toolkit or config().gui_toolkit
diff --git a/kite/quadtree.py b/kite/quadtree.py
index fc5554f..e0ea2f0 100644
--- a/kite/quadtree.py
+++ b/kite/quadtree.py
@@ -4,6 +4,7 @@
 import numpy as num
 from pyrocko import guts
 from pyrocko import orthodrome as od
+from .config import config
 
 from .util import Subject, derampMatrix, property_cached
 
@@ -549,7 +550,8 @@ def clearLeaves(self):
     @property
     def min_node_length_px(self):
         npx = max(self.frame.cols, self.frame.rows)
-        return int(2 ** round(num.log(npx / 64)))
+        return int(2**round(num.log(
+            npx / (2 ** config().quadtree_min_tile_factor))))
 
     def _initTree(self):
         QuadNode.MIN_PIXEL_LENGTH_NODE = (
@@ -607,7 +609,7 @@ def epsilon_min(self):
         """Lowest allowed epsilon
         :type: float
         """
-        return self._epsilon_init * 0.1
+        return self._epsilon_init * config().epsilon_min_factor
 
     @property
     def nan_allowed(self):