# 0.4.0

* Initial multi-GPU support viable for standalone and Spark.
* Refactored the Spark API significantly
* Added CuDNN wrapper
* Performance improvements for ND4J
* Introducing [DataVec](https://github.com/deeplearning4j/datavec): Lots of new functionality for transforming, preprocessing, cleaning data. (This replaces Canova)
* New DataSetIterators for feeding neural nets with existing data: ExistingDataSetIterator, Floats(Double)DataSetIterator, IteratorDataSetIterator
* New learning algorithms for word2vec and paravec: CBOW and PV-DM respectively
* New native ops for better performance: DropOut, DropOutInverted, CompareAndSet, ReplaceNaNs
* Shadow asynchronous datasets prefetch enabled by default for both MultiLayerNetwork and ComputationGraph
* Better memory handling with JVM GC and CUDA backend, resulting in significantly lower memory footprint