<div dir="ltr"><div class="markdown-here-wrapper" style><p style="margin:1.2em 0px!important">Hello all,</p>
<p style="margin:1.2em 0px!important">IPython 3.0 will carry major updates to both the <a href="http://ipython.org/ipython-doc/dev/development/messaging.html">kernel message spec</a> and the <a href="https://github.com/ipython/ipython/pull/6045">notebook document format</a>. The message spec changes landed months ago, and include shims to continue supporting kernels that talk msg spec v4 via adapters. We will backport the new nbformat to 2.3 once it is finalized, so that 2.x users will still be able to read IPython notebooks authored in 3.0 (they will be downgraded to the old nbformat on open).</p>


<p style="margin:1.2em 0px!important">The question under discussion right now: Do we need shims like those in the message specification in the notebook format? The main place where the nbformat is a public API is in nbconvert, where custom templates or preprocessors need to know the nbformat structure. Code such as Jake Vanderplas’ liquid_tags for pelican will need to be updated to work with IPython 3.0. Shims for nbformat would be a lot more complicated than for the message spec, so I want to gauge interest / need before investing too much time in it.</p>


<p style="margin:1.2em 0px!important">-MinRK</p>
<div title="MDH:SGVsbG8gYWxsLDxkaXY+PGJyPjwvZGl2PjxkaXY+SVB5dGhvbiAzLjAgd2lsbCBjYXJyeSBtYWpv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" style="height:0;font-size:0em;padding:0;margin:0">​</div></div></div>