diff --git a/README.rst b/README.rst
index e6759f24..2a113774 100644
--- a/README.rst
+++ b/README.rst
@@ -9,6 +9,10 @@ xarray_ extension for setting and running simulations using the
 xarray's ``Dataset`` structure. It is designed for fast, interactive
 and exploratory modeling.
 
+xarray-simlab is well integrated with other libraries of the PyData
+ecosystem such as `dask <https://docs.dask.org>`_ and `zarr
+<https://zarr.readthedocs.io>`_.
+
 .. _xarray: http://xarray.pydata.org
 .. |Build Status| image:: https://github.com/benbovy/xarray-simlab/workflows/test/badge.svg?branch=master
    :target: https://github.com/benbovy/xarray-simlab/actions?workflow=test
@@ -143,7 +147,6 @@ dask_ libraries. Their licenses are reproduced in the "licenses"
 directory.
 
 .. _pandas: http://pandas.pydata.org/
-.. _dask: http://dask.pydata.org
 
 Acknowledgment
 --------------
diff --git a/doc/about.rst b/doc/about.rst
index 0a5181a6..7aa66ace 100644
--- a/doc/about.rst
+++ b/doc/about.rst
@@ -7,10 +7,13 @@ xarray-simlab provides a framework to easily build custom
 computational models from a collection of modular components, called
 processes.
 
-It also provides an extension to `xarray <https://xarray.pydata.org>`_
-(i.e., labeled arrays and datasets), that connects it to a wide range
-of libraries of the SciPy / PyData stack for processing, analysis,
-visualization, etc.
+It also provides an extension to `xarray <https://xarray.pydata.org>`_ (i.e.,
+labeled arrays and datasets), that connects it to a wide range of Python
+libraries for processing, analysis, visualization, etc.
+
+xarray-simlab is well integrated with other libraries of the PyData
+ecosystem such as `dask <https://docs.dask.org>`_ and `zarr
+<https://zarr.readthedocs.io>`_.
 
 In a nutshell
 -------------
@@ -161,7 +164,6 @@ great sources of inspiration for this project.
   processes. In this project we actually borrow some code from dask
   for resolving process dependencies and for model visualization.
 
-.. _dask: https://github.com/dask/dask
 .. _luigi: https://github.com/spotify/luigi
 .. _django: https://github.com/django/django
 .. _param: https://github.com/ioam/param
diff --git a/doc/conf.py b/doc/conf.py
index 31ea8219..55b8e714 100755
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -39,6 +39,18 @@
     print(f"xarray: {xarray.__version__}, {xarray.__file__}")
 except ImportError:
     print("no xarray")
+try:
+    import dask
+
+    print(f"dask: {dask.__version__}, {dask.__file__}")
+except ImportError:
+    print("no dask")
+try:
+    import zarr
+
+    print(f"zarr: {zarr.__version__}, {zarr.__file__}")
+except ImportError:
+    print("no zarr")
 
 import xsimlab
 
diff --git a/doc/whats_new.rst b/doc/whats_new.rst
index 751880bb..be019a01 100644
--- a/doc/whats_new.rst
+++ b/doc/whats_new.rst
@@ -3,8 +3,16 @@
 Release Notes
 =============
 
-v0.4.0 (Unreleased)
--------------------
+v0.4.0 (7 April 2020)
+---------------------
+
+This is a big release which includes many exciting new features built on top of
+great Python libraries. It is now possible to set default, validate or convert
+model input values just like regular attributes in `attrs
+<https://www.attrs.org>`_, save model input/outputs with `zarr
+<https://zarr.readthedocs.io>`_, run model(s) in parallel using `dask
+<https://docs.dask.org>`_, monitor model runs with a `tqdm
+<https://tqdm.github.io/>`_ progress bar, and much more!
 
 Breaking changes
 ~~~~~~~~~~~~~~~~
@@ -161,8 +169,6 @@ Also, Python 3.4 support has been dropped. It may still work with that
 version but it is not actively tested anymore and it is not packaged
 with conda.
 
-.. _attrs: http://www.attrs.org
-
 Breaking changes
 ~~~~~~~~~~~~~~~~