F# 1.9.1 has been released! The 1.9.1.9 download is available at this link.
I've posted the full release notes in another blog entry. The highlights in this release are:
Active Patterns. Active patterns give a form of extensible pattern matching on abstract values. F# active patterns allow you to pattern match against .NET object values such as XML, System.Type values and LINQ Expression trees. In this redesigned version they become an official part of the language and some novel additions give a lightweight and non-intrusive mechanism to both partial patterns, parameterized patterns and "complete" decompositions (views) of types.
Implicit Class Construction. This lovely feature makes writing classes considerably more succinct and helps to further bridge the gap between type-inferred functional programming and object-oriented programming.
Simpler Quotation Library. The F# Quotation library has been redesigned to use active patterns and to have a much simpler model of types, and as such is now much more powerful. F# Quotations are used to interoperate with LINQ, Accelerator and other meta-programming components.
Methods as first-class values. You can now use .NET methods as functions in many situations, e.g. "map File.ReadAllLines ["a.txt"; "b.txt"]"
Attributes for C Interoperability. StructLayout, FieldLayout etc. now supported
Better IntelliSense. IntelliSense on more expressions, more information in ToolTips.
Syntactic improvements, Bug fixes, Library additions and much more. A whole bunch of things here - more detail in the release notes
Have fun!
don