diff --git a/README.md b/README.md
index 55f62878..fd09fcfc 100644
--- a/README.md
+++ b/README.md
@@ -28,7 +28,7 @@ Owl is currently mostly stable.  Possible future changes are explained in the
 Here is a short example to illustrate interactive components:
 
 ```javascript
-const { Component, QWeb, useState } = owl;
+const { Component, useState } = owl;
 const { xml } = owl.tags;
 
 class Counter extends Component {
@@ -50,7 +50,7 @@ class App extends Component {
   static components = { Counter };
 }
 
-const app = new App({ qweb: new QWeb() });
+const app = new App();
 app.mount(document.body);
 ```
 
@@ -92,7 +92,7 @@ A complete documentation for Owl can be found here:
 
 The most important sections are:
 
-- [Quick Start](doc/quick_start.md)
+- [Quick Start](doc/learning/quick_start.md)
 - [Component](doc/reference/component.md)
 - [Hooks](doc/reference/hooks.md)
 
@@ -127,23 +127,6 @@ Owl components in an application are used to define a (dynamic) tree of componen
      C   D
 ```
 
-**Environment:** the root component is special: it is created with an environment,
-which should contain a [`QWeb` instance](doc/reference/qweb.md). The environment is then automatically
-propagated to each sub components (and accessible in the `this.env` property).
-
-```js
-const env = { qweb: new QWeb() };
-const app = new App(env);
-app.mount(document.body);
-```
-
-The environment is mostly static. Each application is free to add anything to
-the environment, which is very useful, since this can be accessed by each sub
-component. Some good use case for that is some configuration keys, session
-information or generic services (such as doing rpcs, or accessing local storage).
-Doing it this way means that components are easily testable: we can simply
-create a test environment with mock services.
-
 **State:** each component can manage its own local state. It is a simple ES6
 class, there are no special rules:
 
diff --git a/doc/comparison.md b/doc/comparison.md
index 800427ff..4084e159 100644
--- a/doc/comparison.md
+++ b/doc/comparison.md
@@ -274,7 +274,8 @@ class Counter extends Component {
   dispatch = useDispatch();
 }
 
-const counter = new Counter({ store, qweb });
+owl.config.env.store = store;
+const counter = new Counter();
 ```
 
 ## Hooks
diff --git a/doc/learning/environment.md b/doc/learning/environment.md
new file mode 100644
index 00000000..8da07aa5
--- /dev/null
+++ b/doc/learning/environment.md
@@ -0,0 +1,48 @@
+# 🦉 Environment 🦉
+
+An environment is an object which contains a [`QWeb` instance](../reference/qweb.md).
+Whenever a root component is created, it is assigned an environment (see the
+reference section on [environment](../reference/environment.md). This environment
+is then automatically given to each sub components (and accessible in the `this.env` property).
+
+The environment is mostly static. Each application is free to add anything to
+the environment, which is very useful, since this can be accessed by each sub
+component.
+
+Some good use cases for the environment is:
+
+- some configuration keys,
+- session information,
+- generic services (such as doing rpcs, or accessing local storage).
+
+Doing it this way means that components are easily testable: we can simply
+create a test environment with mock services.
+
+For example:
+
+
+```js
+async function myEnv() {
+    const templates = await loadTemplates();
+    const qweb = new QWeb({templates});
+    const session = getSession();
+
+    return {
+        _t: myTranslateFunction,
+        session: session,
+        qweb: qweb,
+        services: {
+            localStorage: localStorage,
+            rpc: rpc,
+        },
+        debug: false,
+        inMobileMode: true,
+    };
+}
+
+async function start() {
+    owl.config.env = await myEnv();
+    const app = new App();
+    await app.mount(document.body);
+}
+```
\ No newline at end of file
diff --git a/doc/readme.md b/doc/readme.md
index af98a1b9..8a1dcb96 100644
--- a/doc/readme.md
+++ b/doc/readme.md
@@ -12,6 +12,9 @@ owl
     QWeb
     Store
     useState
+    config
+        mode
+        env
     core
         EventBus
         Observer
@@ -48,11 +51,18 @@ owl
 
 Note that for convenience, the `useState` hook is also exported at the root of the `owl` object.
 
+## Learning Resources
+
+- [Quick Start: create an (almost) empty Owl application](learning/quick_start.md)
+- [Environment: what it is and what it should contain](learning/environment.md)
+
 ## Reference
 
 - [Animations](reference/animations.md)
 - [Component](reference/component.md)
+- [Configuration](reference/config.md)
 - [Context](reference/context.md)
+- [Environment](reference/environment.md)
 - [Event Bus](reference/event_bus.md)
 - [Hooks](reference/hooks.md)
 - [Misc](reference/misc.md)
@@ -63,10 +73,6 @@ Note that for convenience, the `useState` hook is also exported at the root of t
 - [Tags](reference/tags.md)
 - [Utils](reference/utils.md)
 
-## Learning Resources
-
-- [Quick Start: create an (almost) empty Owl application](learning/quick_start.md)
-
 ## Miscellaneous
 
 - [Comparison with React/Vue](comparison.md)
diff --git a/doc/reference/component.md b/doc/reference/component.md
index 91a49307..35f05ed4 100644
--- a/doc/reference/component.md
+++ b/doc/reference/component.md
@@ -11,7 +11,6 @@
   - [Methods](#methods)
   - [Lifecycle](#lifecycle)
   - [Root Component](#root-component)
-  - [Environment](#environment)
   - [Composition](#composition)
   - [Event Handling](#event-handling)
   - [Form Input Bindings](#form-input-bindings)
@@ -81,8 +80,8 @@ a state object is defined, by using the `useState` hook. It is not mandatory to
 ## Reference
 
 An Owl component is a small class which represents a component or some UI element.
-It exists in the context of an environment (`env`), which is propagated from a
-parent to its children. The environment needs to have a QWeb instance, which
+It exists in the context of an [environment](environment.md) (`env`), which is propagated from a
+parent to its children. The environment needs to have a [QWeb](qweb.md) instance, which
 will be used to render the component template.
 
 Be aware that the name of the component may be significant: if a component does
@@ -441,49 +440,12 @@ of an Owl application has to be created manually:
 ```js
 class App extends owl.Component { ... }
 
-const qweb = new owl.QWeb({ templates: TEMPLATES });
-const env = { qweb: qweb };
-const app = new App(env);
+const app = new App();
 app.mount(document.body);
 ```
 
-The root component needs an environment.
-
-### Environment
-
-In Owl, an environment is an object with a `qweb` key, which has to be a
-[QWeb](qweb.md) instance. This qweb instance will be used to render everything.
-
-The environment is meant to contain (mostly) static global information and
-methods for the whole application. For example, settings keys (`mode` to determine
-if we are in desktop or mobile mode, or `theme`: dark or light), `rpc` methods,
-session information, ...
-
-The environment will be given to each child, unchanged, in the `env` property.
-This can be very useful to share common information/methods. For example, all
-rpcs can be made through a `rpc` method in the environment. This makes it very
-easy to test a component.
-
-Updating the environment is not as simple as changing a component's state: its
-content is not observed, so updates will not be reflected immediately in the
-user interface. There is however a mechanism to force root widgets to rerender
-themselves whenever the environment is modified: one only needs to call the
-`forceUpdate` method on the QWeb instance. For example, a responsive environment
-could be done like this:
-
-```js
-function setupResponsivePlugin(env) {
-  const isMobile = () => window.innerWidth <= 768;
-  env.isMobile = isMobile();
-  const updateEnv = owl.utils.debounce(() => {
-    if (env.isMobile !== isMobile()) {
-      env.isMobile = !env.isMobile;
-      env.qweb.forceUpdate();
-    }
-  }, 15);
-  window.addEventListener("resize", updateEnv);
-}
-```
+The root component does not have a parent nor props. It will be setup with an
+[environment](environment.md) (located in `owl.config.env`).
 
 ### Composition
 
@@ -986,7 +948,7 @@ of the props. Here is how it works in Owl:
 - `props` key is a static key (so, different from `this.props` in a component instance)
 - it is optional: it is ok for a component to not define a `props` key.
 - props are validated whenever a component is created/updated
-- props are only validated in `dev` mode (see [tooling page](../tooling.md#development-mode))
+- props are only validated in `dev` mode (see [config page](config.md#mode))
 - if a key does not match the description, an error is thrown
 - it validates keys defined in (static) `props`. Additional keys given by the
   parent will cause an error.
diff --git a/doc/reference/config.md b/doc/reference/config.md
new file mode 100644
index 00000000..5d151539
--- /dev/null
+++ b/doc/reference/config.md
@@ -0,0 +1,56 @@
+# 🦉 Config 🦉
+
+The Owl framework is designed to work in many situations.  However, it is
+sometimes necessary to customize some behaviour.  This is done by using the
+global `config` object. It currently has two keys:
+
+- [`mode`](#mode),
+- [`env`](#env).
+
+## Mode
+
+By default, Owl is in _production_ mode, this means that it will try to do its
+job fast, and skip some expensive operations. However, it is sometimes necessary
+to have better information on what is going on, this is the purpose
+of the `dev` mode.
+
+Owl has a mode flag, in `owl.config.mode`. Its default value is `prod`, but
+it can be set to `dev`:
+
+```js
+owl.config.mode = "dev";
+```
+
+Note that templates compiled with the `prod` settings will not be recompiled.
+So, changing this setting is best done at startup.
+
+An important job done by the `dev` mode is to validate props for each component
+creation and update. Also, extra props will cause an error.
+
+## Env
+
+An Owl application needs an [environment](environment.md) to be executed. The
+environment has an important key: the [QWeb](qweb.md) instance, which will render
+all templates.
+
+Whenever a root component is mounted, Owl will take the environment from
+`owl.config.env` and use it to setup the component (and its children).
+
+- if no environment was setup, an empty environment will be generated,
+- if an environment exists, but does not have a QWeb key, a new QWeb instance
+  will then be added to the environment.
+
+The correct way to customize an environment is to simply modify `owl.config.env`
+before the first component is created:
+
+```js
+owl.config.env = {
+    _t: myTranslateFunction,
+    user: {...},
+    services: {
+        ...
+    },
+};
+const app = new App();
+app.mount(document.body);
+```
diff --git a/doc/reference/context.md b/doc/reference/context.md
index 624d5b01..abdbec0a 100644
--- a/doc/reference/context.md
+++ b/doc/reference/context.md
@@ -28,10 +28,7 @@ context, and add it to the environment:
 
 ```js
 const deviceContext = new Context({ isMobile: true });
-const env = {
-  qweb: new QWeb({ templates: TEMPLATES }),
-  deviceContext
-};
+owl.config.env.deviceContext = deviceContext;
 ```
 
 If we want to make it completely responsive, we need to update its value whenever
diff --git a/doc/reference/environment.md b/doc/reference/environment.md
new file mode 100644
index 00000000..40e6aa10
--- /dev/null
+++ b/doc/reference/environment.md
@@ -0,0 +1,18 @@
+# 🦉 Environment 🦉
+
+An environment is an object which contains a [`QWeb` instance](qweb.md). Whenever a root component is created, it is assigned an environment. This environment
+is then automatically given to each sub component (and accessible in the `this.env` property).
+
+```
+    Root
+    /  \
+   A    B
+```
+
+This way, all components share the same `QWeb` instance.
+
+Note: some additional information can be found here:
+
+- [What should go into an environment?](../learning/environment.md)
+- [Customizing an environment](config.md#env)
+
diff --git a/doc/reference/qweb.md b/doc/reference/qweb.md
index 6815cbd5..b27fabbd 100644
--- a/doc/reference/qweb.md
+++ b/doc/reference/qweb.md
@@ -159,7 +159,7 @@ Its API is quite simple:
   ```
 
 In some way, a `QWeb` instance is the core of an Owl application. It is the only
-mandatory element of an [environment](component.md#environment). As such, it
+mandatory element of an [environment](environment.md). As such, it
 has an extra responsibility: it can act as an event bus for internal communication
 between Owl classes. This is the reason why `QWeb` actually extends [EventBus](event_bus.md).
 
diff --git a/doc/reference/router.md b/doc/reference/router.md
index 496b8e84..2b6e4020 100644
--- a/doc/reference/router.md
+++ b/doc/reference/router.md
@@ -67,6 +67,9 @@ function makeEnvironment() {
     await env.router.start();
     return env;
 }
+
+owl.config.env = makeEnvironment();
+// create root component here
 ```
 
 Notice that the router needs to be started. This is an asynchronous operation
diff --git a/doc/tooling.md b/doc/tooling.md
index 6e0a5841..98f1e360 100644
--- a/doc/tooling.md
+++ b/doc/tooling.md
@@ -3,7 +3,6 @@
 ## Content
 
 - [Overview](#overview)
-- [Development Mode](#development-mode)
 - [Playground](#playground)
 - [Benchmarks](#benchmarks)
 - [Single File Component](#single-file-component)
@@ -21,26 +20,6 @@ by using a static http server. A simple python
 server is available in `server.py`. There is also a npm script to start it:
 `npm run tools` (and its version with a watcher: `npm run tools:watch`).
 
-## Development Mode
-
-By default, Owl is in _production_ mode, this means that it will try to do its
-job fast, and skip some expensive operations. However, in some cases, it is
-convenient to have better information on what is going on, this is the purpose
-of the dev mode.
-
-Owl has a mode flag, in `owl.__info__.mode`. Its default value is `prod`, but
-it can be set to `dev`:
-
-```js
-owl.__info__.mode = "dev";
-```
-
-Note that templates compiled with the `prod` settings will not be recompiled.
-So, changing this setting is best done at startup.
-
-An important job done by the `dev` mode is to validate props for each component
-creation and update. Also, extra props will cause an error.
-
 ## Playground
 
 The playground is an important application designed to help learning and