https://www.visualstudio.com/downloads/download-visual-studio-vs。
F# 4.0 包含新的语言特性：
构造函数作为一级函数
可变值的使用简化
支持高维的数组
支持方法中的静态参数
简化列表的语法
简化 printf 函数的使用
GC 优化提升性能
API 改进：
标准化和扩展 Array, List 和 Seq 模块
New APIs for 4.0: chunkBySize, contains, except, findBack, findInstanceBack, indexed, item, mapFold, mapFoldBack, sortByDescending, sortDescending, splitInto, tryFindBack, tryFindIndexBack, tryHead, tryItem, tryLast
其他新 API
Option.filter, Option.toObj, Option.ofObj, Option.toNullable, Option.ofNullable
String.filter
Checked.int8, Checked.uint8
Async.AwaitTask (non-generic)
WebClient.AsyncDownloadFile, WebClient.AsyncDownloadData
tryUnbox, isNull
其他值得关注的改进：
New active pattern to match constant Decimal in quotations
Slicing support for lists
Support for consuming high-rank (> 4) arrays
Support for units of measure in printf-family functions
Support for constructors/class names as first-class functions
Improved exception stack traces in async code
Automatic mutable/ref conversion
Support for static arguments to provided methods
Support for non-nullable provided types
Added NonStructuralComparison module containing non-structural comparison operators
Support for rational exponents in units of measure
Give fsi.exe, fsiAnyCpi.exe nice icons
Microsoft. optional in namepsace paths from FSharp.Core
Support for extension properties in object initializers
Pre-support (not yet used) for additional nativeptr intrinsics
Simplified, more robust resolution of type references in quotations
Support for inheritance of types that have multiple interface instantiations
Extended preprocessor grammar
Support for implicit quotation of expressions used as method arguments
Support for multiple properties in [
Eliminate tuple allocation for implicitly returned formal arguments
Perf: fsc.exe now uses GCLatencyMode.Batch
Perf: Improved hash/compare/distinctBy/groupBy performance
Perf: Seq.toArray perf improvement
Perf: Use OptimizedClosures.FSharpFunc in seq.fs where applicable
Perf: Use literals and mutable variables instead of ref cells for better performance in SHA1 calc
Perf: Use smart blend of System.Array.Copy and iterative copy for array copies
Perf: Change Seq.toList to mutation-based to remove reliance on List.rev
Perf: Change pdbClose to test if files are locked before inducing GCs
Perf: Use server GC mode for compiler
Visual Studio 方面的改进：
Updated all templates (except tutorial) to include AssemblyInfo.fs setup in the same manner as default C# project templates
Add keyboard shortcuts for FSI reset and clear all
Improved debugger view for Map values
Improved performance reading stdout/stderr from fsi.exe to F# Interactive window
Support for VS project up-to-date check
Improved project template descriptions, make it clearer how to target Xamarin platforms
Intellisense completion in object initializers
Add menu entry "Open folder in File Explorer" on folder nodes
Intellisense completion for named arguments
Alt+Enter sends current line of code to interactive if there is no selection
Support for debugging F# scripts with the VS debugger
Add support for hexadecimal values (like 0xFF) ??to MSBuild property BaseAddress
Updated menu icons used for F# interactive to align with other VS interactive windows
此外还有写 bug 修复。
F#是由微软发展的为微软.NET语言提供运行环境的程序设计语言，是函数编程语言（FP，Functional Programming），函数编程语言最重要的基础是Lambda Calculus。它是基于OCaml的，而OCaml是基于ML函 数程式语言。有时F# 和 OCaml 的程式是可以交互编译的。
F#已经接近成熟，支援Higher-Order Function、Currying、Lazy Evaluation、Continuations、Pattern Matching、Closure、List Processing、Meta-Programming。这是一个用于显示.NET在不同编程语言间互通的程序设计，可以被.NET中的任意其它代码编 译和调用。
F#将被集成在Visual Studio 2010中，含有对.Net Framework的完全支持。
软件详情：https://github.com/Microsoft/visualfsharp/blob/fsharp4/CHANGELOG.md
来自:开源中国社区