Performance improvements in the way temporary files are used. Whereas previous versions of this product created a separate temporary file for every item added to or updated in a zip archive, this version tries to use a single temporary file for an operation and attempts to make changes in-place. Operations involving a large number of items can therefore be completed more quickly, due to reduced disk usage.
This version is built with .NET Framework 3.5 for Visual Studio 2008. The corresponding .NET 4 build is v5.0.