User:Duplode/Awkward squad plan

Mutable objects

 * Introduction: suggest typical use cases − low-level interfaces with external libraries, algorithms that demand mutability, huge volumes of data.
 * IORefs: basic example, point out concurrency pitfalls, link to Concurrency.
 * ST: Isolated mutability. A word or two on existentials. A hashtables example. (A link to, or an adaptation of, augustuss' quicksort?)
 * Other references: Haskell Cafe thread on the need for global mutable state.

Concurrency

 * MVar
 * STM
 * Validate the memoisation example currently there.
 * Integrate the STM example from Haskell/Practical monads
 * References: SPJ's Awkward Squad

Effectful streaming

 * The pitfalls of lazy IO.
 * Probably use Pipes, but also mention Conduit.

Exceptions

 * ExceptT will likely be mentioned elsewhere already.
 * What else to include? (Control.Exception? Gabriel's errors (see also http://www.haskellforall.com/2012/07/errors-10-simplified-error-handling.html)?)