Release Notes: https://github.com/DynamoDS/Dynamo/wiki/Release-Notes#342
Language guide: https://dynamobim.org/wp-content/links/DesignScriptGuide.pdf
Nugets: https://www.nuget.org/packages/DynamoVisualProgramming.Core/3.4.2.7731
You can also download the release version from https://dynamobuilds.com/