The next major release of F# will be Dev 17.0

• Language F# Language Version will be 6.0
• FSharp.Core.dll version will be 6.0.0.0
• FSharp.Core nuget package will be 6.0.0

Language version 6.0 will be added and will have enabled:

• LanguageFeature.OverloadsForCustomOperations, languageVersion60
• LanguageFeature.ExpandedMeasurables, languageVersion60
• LanguageFeature.ResumableStateMachines, languageVersion60
• LanguageFeature.StructActivePattern, languageVersion60
• LanguageFeature.PrintfBinaryFormat, languageVersion60
• LanguageFeature.UseBindingValueDiscard, languageVersion60
• LanguageFeature.NonVariablePatternsToRightOfAsPatterns, languageVersion60
• LanguageFeature.AttributesToRightOfModuleKeyword, languageVersion60

And also this active PR

• Additional type directed conversions

And possibly these active PRs

• type resolved arr[idx]
• RFC FS-1108 - Undentation frenzy