Zip format compatibility improvements, increased flexibility, and archive optimizations. Specifically, Zip file sizes can be optimized and their creation made more efficient because developers can now decide whether folder entries should be written to the zip archive. Compatibility with Xceed Real-Time Zip for .NET / .NET CF / Silverlight is improved and flexibility is increased in general, as it is now possible to zip using the Deflate format without compression. Resource management has been improved in a way that will help programmers streamline their application logic during development, thanks to a property that returns the number of pending actions remaining to be done on an archive. The stream buffer size of the base file class is now configurable, increasing flexibility and potentially increasing performance based on factors such as the media involved.

Various bug fixes are also provided. 

(The corresponding .NET 2.0-3.5 version for this release is v4.3.)