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F* language

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This package was approved by moderator flcdrg on 5/6/2017.

F*: An ML-like language aimed at program verification

Build status


This package will install F* language with compatable version of z3.
It is recommended that you remove your z3 package and then install F*

F* website

More information on F* can be found at




The F* tutorial provides a first taste of verified programming in
F*, explaining things by example.


The F* wiki contains additional, usually more in-depth, technical
documentation on F*.

Editing F* code

You can edit F* code using your favourite text editor, but Emacs,
Atom, and Vim have extensions that add special support for F*,
including syntax highlighting and interactive development. More
details on editor support on the F* wiki .

Executing F* code

By default F* only verifies the input code, it does not compile or execute it.
To execute F* code one needs to translate it to either OCaml or F#, using
F*'s code extraction facility---this is invoked using the command line
argument --codegen OCaml or --codegen FSharp. More details on
executing F* code on the F* wiki .

Community mailing list

The fstar-club mailing list is dedicated to F* users. Here is where
all F* announcements are made to the general public (e.g. for
releases, new papers, etc) and where users can ask questions, ask for
help, discuss, provide feedback, announce jobs requiring at least 10
years of F* experience, etc.

List archives are public, but only members can post.
Join here!

Slack channel

Users can also ask questions on the #fstar Slack channel at
< >

Reporting issues

Please report issues using the F* issue tracker on GitHub.
Before filing please use search to make sure the issue doesn't already exist.
We don't maintain old releases, so if possible please use the
online F* editor or directly the GitHub sources to check
that your problem still exists on the master branch.


The F* for the masses blog is also expected to become an important
source of information and news on the F* project.


This new variant of F* is released under the Apache 2.0 license;
see LICENSE for more details.

To install F* language, run the following command from the command line or from PowerShell:

C:\> choco install fstar --version

To upgrade F* language, run the following command from the command line or from PowerShell:

C:\> choco upgrade fstar --version


  • tools\chocolateyinstall.ps1 Show
    $ErrorActionPreference = 'Stop'; # stop on all errors
    Install-ChocolateyZipPackage -packageName 'fstar' -UnzipLocation $(Split-Path -Parent $MyInvocation.MyCommand.Definition) -Url64 '' -checksum64 '3F5EFB7F99F371C5A842C9D7F2F42C741AC786F788B00F77A6DB606E4AE51189' -checksumType64 'sha256'

Virus Scan Results

In cases where actual malware is found, the packages are subject to removal. Software sometimes has false positives. Moderators do not necessarily validate the safety of the underlying software, only that a package retrieves software from the official distribution point and/or validate embedded software against official distribution point (where distribution rights allow redistribution).

Chocolatey Pro provides runtime protection from possible malware.


This package has no dependencies.

Package Maintainer(s)

Software Author(s)

  • FStarLang


Release Notes

This is a big release with lots of important changes compared to v0.9.2.0 exactly a year ago:
- Predicative hierarchy of universes with universe polymorphism
- Uniform syntax between expressions and types allowing rich type-level computation
- Dijkstra Monads for Free (
- Extraction to C via KreMLin (
- New parser based on Menhir
- New pretty printer for surface syntax and fstar --indent
- Changed default effect to Tot
- Strict positivity check for inductives
- New synatax for inductive type projectors and discriminators
- Better semantics for module open and support for local opens
- Better dependency analysis
- Better error locations for Z3 failures
- Replaced Z3 timeouts with machine independent resource limits
- Cleaned up libraries and examples (a bit)
- Improvements to interactive mode
- Docker builds
- Fixed a ton of bugs (262 closed GitHub issues)

Version History

Version Downloads Last updated Status
F* language 51 Tuesday, August 28, 2018 approved
F* language 296 Tuesday, September 5, 2017 approved
F* language 244 Wednesday, May 3, 2017 approved

Discussion for the F* language Package

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  • This discussion is only about F* language and the F* language package. If you have feedback for Chocolatey, please contact the google group.
  • This discussion will carry over multiple versions. If you have a comment about a particular version, please note that in your comments.
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  • Tell us what you love about the package or F* language, or tell us what needs improvement.
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