.NET Core 3.0 Preview 6 has been released as of June 12th. You can grab it here : https://dotnet.microsoft.com/download/dotnet-core/3.0
What’s Included
The official blog post from Microsoft is here : https://devblogs.microsoft.com/dotnet/announcing-net-core-3-0-preview-6/ . But of course if you want the cliff notes then…
Docker Images For ARM64
Previously docker images for .NET Core were only available for X64 systems, however you can now grab ’em for ARM64 too!
Ready To Run Images
Probably the most interesting thing contained in this release is the “Ready To Run” compilation ability. If you’ve ever used NGEN in previous versions of the .NET Framework, or attempted to some ahead of time jitting to improve your applications startup performance, then this is for you.
Better Assembly Linking
It’s always been possible to publish self contained applications in .NET Core that don’t require the runtime to be present on the destination machine. Unfortunately this sometimes made self contained apps (even one’s that did nothing but print Hello World!) become massive. Preview 6 contains a way to trim the required assemblies to reduce the footprint by almost half.
HTTP/2 Support In HTTPClient
HTTP/2 support has reached .NET Core! The default is still HTTP/1.1, but you are now able to opt in to create connections using a specific version. HTTP/2 opens up the world of multiplexed streams, header compression and better pipelining.
Worth Updating?
Probably the biggest thing for most developers in this version is HTTP/2 support. It’s likely something that will become defacto in the future so if you want to get ahead of the curve, get stuck in!
Ready To Run images are also pretty huge. If you remember that famous blog post from the Bing team around performance improvements they gained from switching to .NET Core 2.1 (https://devblogs.microsoft.com/dotnet/bing-com-runs-on-net-core-2-1/), a big factor was ahead of time compiling of the code. So it’s definitely going to change the game for a lot of companies running .NET Core code.
