Support for Linux and Apple macOS build agents – note that development is still only officially supported on Microsoft Visual Studio for Windows.
Improved responsiveness of PostSharp Tools for Microsoft Visual Studio – making PostSharp a well-behaved asynchronous extension.
Support for shared and multi-targeted projects - PostSharp Tools for Microsoft Visual Studio now works properly with files that are shared between several projects, and with multi-targeted projects.
Support for per-monitor awareness of DPI – resulting in a much smoother experience.
Solved aspect ordering issue on async methods – for instance, it is now possible to add a code contract to the return value of a cached async method.
Contracts: ability to customize the type of thrown exceptions - PostSharp now use a factory pattern to instantiate exceptions, so you can completely customize the exceptions thrown by standard contracts.