Please check out our release note:
http://www.emgu.com/wiki/index.php/Version_History#Emgu.CV-4.9.0
Documentation can be found here:
http://www.emgu.com/wiki/files/4.9.0/document
"libemgucv-windesktop-4.9.0.5494.exe" is an installer that will install Emgu CV (without CUDA support) into your workstation, it will also install debugger visualizer for Visual Studio 2022 & Visual Studio 2019.
"libemgucv-windesktop-4.9.0.5494.zip" contains all files in the above installer, but will not install the debugger visualizer for visual studio.
The 3 "nupkg" files are nuget packages for this release with CUDA support, we are not able to upload them to nuget.org due to file size limit. (nuget.org has a size limit of 250MB but the Emgu.runtime.windows.cuda.dnn.cnn.infer package size is larger than that) Instructions on how to use them can be found here:
https://www.emgu.com/wiki/index.php/Download_And_Installation#CUDA_nuget_package_4.5.1.2B