This information applies to version(s): 6
With Nik Collection 6 we've completed the complete refresh of the software suite*: Our team completely rewrote the entire software from scratch using modern programming languages. Changes that you can see: user interface (UI) and user experience (UX) improvements. Changes that you cannot see: Modern, more efficient coding languages, starting "merging Nik Collection Engine with DxO Engine", eradication of legacy bugs, compatibilities with HDPI screens. All this is a tremendous rework and is what the team could achieve in the allocated time.
* Nik Sharpener and Nik HDR Efex updates coming in Nik Collection 6.3 which will be released before the end of summer (free updates will be provided for purchasers of version 6).