+ GHC now defaults to the Haskell 2010 language standard.
+ </para>
+
+ <para>
+ Libraries are not quite so straightforward. By default, GHC
+ provides access to the <literal>base</literal> package,
+ which includes the Haskell 2010 libraries, albeit with a few
+ minor differences. For those who want to write strictly
+ standards-conforming code we also provide
+ the <literal>haskell2010</literal> package which provides
+ the precise APIs specified by Haskell 2010, but because the
+ module names in this package overlap with those in
+ the <literal>base</literal> package it is not possible to
+ use both <literal>haskell2010</literal>
+ and <literal>base</literal> at the same time (this also
+ applies to the <literal>array</literal> package). Hence to use
+ the Haskell 2010 libraries you should hide
+ the <literal>base</literal> and <literal>array</literal>
+ packages, for example with GHCi:
+<screen>
+$ ghci -package haskell2010 -hide-package base -hide-package array
+</screen>
+ If you are using Cabal it isn't necessary to
+ hide <literal>base</literal> and <literal>array</literal>
+ explicitly, just don't include them in your <literal>build-depends</literal>.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ On POSIX platforms, there is a new I/O manager based on
+ epoll/kqueue/poll, which allows multithreaded I/O code to
+ scale to a much larger number (100k+) of threads.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ The inliner has been overhauled, which should in general
+ give better performance while reducing unnecessary code-size
+ explosion.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ Large parts of the runtime system have been overhauled, in
+ particular the machinery related to blocking and wakeup of
+ threads and exception throwing (<literal>throwTo</literal>).
+ Several instances of pathological performance have been
+ fixed, especially where large numbers of threads are
+ involved.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ Due to changes in the runtime system, if you are
+ using <literal>Control.Parallel.Strategies</literal> from
+ the <literal>parallel</literal> package, please upgrade to
+ at least version 2 (preferably version 3). The
+ implementation of Strategies
+ in <literal>parallel-1.x</literal> will lose parallelism
+ with GHC 6.14.1.