=====================
 Development version
=====================

This document describes in-flight development work.

Redesigned IPython notebook user interface
------------------------------------------

.. add details

Other new features
------------------

* **%install_ext**: A new magic function to install an IPython extension from
  a URL. E.g. ``%install_ext https://bitbucket.org/birkenfeld/ipython-physics/raw/d1310a2ab15d/physics.py``.

* The :envvar:`IPYTHON_DIR` environment variable, introduced in the Great
  Reorganization of 0.11 and existing only in versions 0.11-0.13, has been
  deprecated. As described in :ghissue:`1167`, the complexity and confusion of
  migrating to this variable is not worth the aesthetic improvement. Please use
  the historical :envvar:`IPYTHONDIR` environment variable instead.

* The default value of *interactivity* passed from
  :meth:`~IPython.core.interactiveshell.InteractiveShell.run_cell` to
  :meth:`~IPython.core.interactiveshell.InteractiveShell.run_ast_nodes`
  is now configurable.

Backwards incompatible changes
------------------------------

* The exception :exc:`IPython.core.error.TryNext` previously accepted
  arguments and keyword arguments to be passed to the next implementation
  of the hook. This feature was removed as it made error message propagation
  difficult and violated the principle of loose coupling.