🚀 Fable 5.7.0 is officially live! 🎉

This release brings massive performance upgrades under the hood for Python:

- DU pattern matching: 6-10x speed up! 🏎️
- Sequences: 1.6x faster!

#fsharp

Fable 5.6 is officially here! 🚀

📁 Expanded System.IO API support (Path and Directory) for JS & Python.

🤖 100% automated release process achieved for the first time!

#fsharp

🚀 Fable 5.0.0-alpha.14 is out!

This one has a big focus on Python and adding support for Nullness to Fable (both your project and dependencies needs to be written with nullness in mind for it to work)

To benefit from all the new features you need to use Fable.Core beta too

1/

🚀 Fable 5.0.0-alpha.13 is out!

This release fixes several Python-related bugs and lays the groundwork for smoother integration with JavaScript front end frameworks.

#fsharp

It has been a while since we announce a new release, but don't worry we have been cooking a lot.

Here are the Changelogs for Fable 5.0.0-alpha 10 & 11

#fsharp

Fable 5 alpha.5 is available.

This time we add support for new APIs and fix the CLI parser to not fail silently on unknown arguments.

#fsharp

Happy new year! 🎉

To start this new year, we have a new alpha version of Fable 5.

#fsharp

Fable 4.23.0 is here 🎉

Rust users can enjoy more features and benefits from fixes.

TypeScript, code generation got severals fixes and JavaScript got a regression compared to Fable 2 fixed 😱.

We also welcome a new contributor ✨

#fsharp

Fable 4.22.0 is out 🎉

Come get the latest improvements for Rust target, and some more for Python and JavaScript.

#fsharp

Fable 4.21.0 is out 🎉

Using `jsOptions` via TypeScript target now generate typed code, so you can enjoy your types even when doing some interop.

It also improves FormattableString and Uri supports.

Python also received some love with a fix when reporting errors.

#fsharp

Fable 4.20.0 has been released.

It had new features for Rust and if you use Decimals with JavaScript target you want to upgrade to avoid issues with comparisons.

#fsharp

Someone has been busy submitting fixes for Fable today.

So we Fable 4.19.1 ready 🎉

Fable 4.19 is out

This is a small one which fix a bug which has been under cover for a long time.

Fable 4.18 is available 🎉

One big new feature is that Fable now supports static members in interfaces which was introduced in F# 8.

We also fixed @fable-org/fable-compiler-js package when used from NPM.

Fable 4.17 is out 🎉

Since the last release, we accumulated several fixes and improvements, they are now available to everyone.

Thanks to everyone who reported issues and the different contributors.

#fsharp

No release can be too small, so today we have 1 feature introduced with Fable 4.16.0

If you use this new API please make sure to read the compatibility documentation because there are some limitations coming with it.

fable.io/docs/javascrip…

#fsharp

Fable 4.15.0 is out

No fancy new features, but several bug fixes which is also important to do :)

#fsharp

To kick March in a bang 💥

Today we released Fable 4.14 which improves signature files support and also implements all possible custom format for DateTime when targeting JS/TS.

Fable 4.13.0 has been released.

This release contains fixes and addition for various target of Fable.

Most notably StringBuilder should be more efficient and for JavaScript accessing an array out of bound now fails to align on .NET behaviour. Perhaps, the oldest bug of Fable?

Fable 4.12.1 is out 🎉

- Better support for `Result` and `ListCollector`
- Various improvements
- All Fable NPM packages have been migrated to "fable-org" scope
- Start exploring a better resolution mechanism we will talk more about it in the future

Thanks to all contributors

First release of 2024 is here and there is a lot in it.

Please refer to the changelog for more information, it contains too many things to make the usual highlights (which is a good thing) 🎉

Thank you to all the contributors. ❤️

As we continue our effort to improve Fable #python, a new version of Fable has been released.

It also update FCS to a newer version and include fixes for string.IndexOfAny for most of the languages.

Fable 4.7.0 is out.

It fix a bug where fable_modules was missing the .gitignore file sorry if we polluted your git history 🙈

It also include several fixes for Python, thanks to the community reports and @dbrattli work.

There was also some performance improvements contributed

Fable 4.6.0 has been released.

This release has a strong focus on improving Python support.

#fsharp

Fable 4.5.0 is out, see the changelog to learn more about it

With yesterday release, users reported lot of F# warnings being generated.

More specifically code 3560, This copy-and-update record expression changes all fields of record type [...]

We made a maintenance release to disable this warning by default.

New release of Fable and Fable.Core.

Main changes are:

- Increase the (un)curry limit
- Drop support of Python 3.9, Fable supports last 3 versions: 3.10, 3.11 and 3.12
- Update FCS to test if latest F# features will works
- [JS] Add full support for `NumberConstructors` API

Two releases in the same week?

Yes, you heard it right, a new version is out reverting a breaking change and improving error messages when parsing some data.

In Python F# async are now running using asyncio mainloop, making conversion between F# Async and Python task easier.

A maintenance fix has been released this weekend.

It focus on fixing some regression that happened in the Python target.

Thanks @dbrattli

A new release is out !!!

It contains several fixes regarding Fable -> JavaScript interop.

This release also focus on improving the user experience when working on multiple targets, and making the Fable.Core API more consistent.

Fable 4.1.4 has been released:

- Fix source maps support which was broken in Fable 4.1.3 🙈
- Fix a regression when trying to type test interfaces declared in F# code

It also has a bunch of improvements made on the Rust target.

Fable 3 maintenance release making the transition period to Fable 4 easier.

This release prevents Fable from hanging if run with .NET 7. It also reports errors if you try to load Fable 4 plugins.

If you provide Fable 3 templates, we encourage that you update it to Fable 3.7.22.

The new JSX compilation was announced only a few days ago, and @DelnegOfficial has already used to write the frontend of a Chat app running on Django. Check it out! github.com/Bearle/django_…

It looks even nicer with the syntax highlighting. Where are the frontiers between F# and JSX? :)

Use JSX with #fsharp in your @FableCompiler React apps to integrate with 3rd party components or if you just prefer the syntax. Learn how in our latest blog post: fable.io/blog/2022/2022…

Looking at the syntax, it may be hard to believe. But this is an actual #fsharp React app.

At #ndcoslo, @dbrattli introduced Fable Python: a VS Code extension that allows you execute #fsharp code directly into Python Interactive. We hope @teknikal_wizard likes it! marketplace.visualstudio.com/items?itemName…

Typescript compilation is progressing quickly ✈️ Soon you'll be able to interact with union types with the same type safety as in #fsharp!

Fable 3.7.18 has been released. Among other fixes, this version is finally compatible with FSharp.Text.RegexProvider! fsprojects.github.io/FSharp.Text.Re…

ncave, Alex Swan and @dbrattli are on 🔥🔥🔥!!!

Thanks to ncave we have just released the experimental repl for Fable 4 (mind the URL), letting you pick the language target and see how #fsharp translates to JS, Python, Rust and Dart! fable.io/repl4/

🌈Did you notice the hype around @solid_js lately?

Now you can try it out with #fsharp and @zaid_ajaj Feliz API with @FableCompiler Snake Island! github.com/alfonsogarciac…

Thank you @cannorin_pub for this wonderful contribution to ts2fable! 👏👏👏

Now you can easily use Typescript tagged unions from your #fsharp/@FableCompiler bindings (check the --tagged-union option) 🤖

fable.io/ts2fable/

#fsharp ❤️ @FlutterDev

Look who has changed their Github profile!

Done! fable.io/repl/

Thanks to @cannorin_pub, next version of Fable will be able to interact with Typescript tagged unions as if they were #fsharp union types 👏

Fable ❤️ @buildWithLit: Fable.Lit 1.0 is out! A new superpower for #fsharp developers fable.io/Fable.Lit/

Another great example for the REPL by @robertpi! Check Games/Undertone and try to build your favorite melody. Who said #csharp doesn't go along with #fsharp? We're talking about the notes, of course ;) fable.io/repl/

BooksBaum is doing an awesome job to improve ts2fable, the converter of Typescript declarations into #fsharp! Use it as a cli tool (check Readme) or directly from the website fable.io/ts2fable/

Look who's back!

If you have a Fable project and want to share it with others, remember to add it to fable.io/community to make it easier to find. github.com/fable-compiler…

Do you know Issie? It stands for "Intuitive Schematic Simulator and Interactive Editor", and it's an @electronjs app used at Imperial College London written in #fsharp and compiled with @FableCompiler tomcl.github.io/issie/

Having fun with fractals and webGL in Fable 3 REPL by @mark_pattison fable.io/repl3/#?sample…

.@zaid_ajaj live right now showing how to build a React app with @safe_stack and #nagareyama! youtube.com/watch?v=Uq4qyH…

Now you can test the latest #fsharp 4.7 (and preview) features in the Fable REPL! Remember to hard reload your browser if you don't see the changes :) fable.io/repl/

That's all folks!

A big thank you to the speakers, the participants, the organization team and all the people who believed in #fableconf. You made it come true!

Thank you and see you next time! 😊

This morning, we'll also have @DiEsmerio's workshop at #fableconf. If you already are using Elmish on the client side, check this workhop to know how to connect to your backend and keep the same mindset everywhere!

Good morning #fableconf!
It's saturday and it's breakfast time. 🙌
Rendez-vous at @Axxes_IT buildings today.😊

We know that it's not easy to make an event like #fableconf happen! So warm thanks to @verdonckflorian and his team from @Axxes_IT for making this possible in the lovely city of Antwerp!

You guys rock!

#Fableconf 🥳🥳🥳

Hey #fableconf friends, while you're enjoying your lunch and the nice city of Antwerpen, here's a little incentive about @virtualblackfox's workshop tomorrow at 11:40 featuring some real #reactjs magic. 🧙‍♂️✨

More details here: fable.io/fableconf/#age…

Hey #Fableconf friends. We hope you enjoyed this first morning! It's almost Lunch time now. Bon appétit!

BTW, for those who wish to join us this evening for a special #fableconf dinner, could please fill this form: tinyurl.com/y2cf67l6

Thanks! Hope we'll see you there!

Hey #fableconf friends!
Let's start the day the right way: share some coffee and meet together.
Our introductory breakfast's ready!

Tip: throughout the day check #FableConf tag on twitter to get information about what's going on.

Hey #FableConf! interested in Azure Storage Accounts? Then @BrettRowberry will show you how to create an account manager using .NET Azure SDKs, the Giraffe web server and Fable. 🚀 #fsharp fullstack delight!🚀

More details here: fable.io/fableconf/#age…

Hey #FableConf friends!
You really want to connect the dots between #js and #fsharp? You've been reading our docs and blog posts and still have questions? Or you just want to practice with an expert? Then join @zaid_ajaj saturday morning 😊

Details: fable.io/fableconf/#age…

Hey, #fsharp #js #nodejs friends, we wish to thank you for your support during our #FableConf sales. 👍

We'll be very happy to see everybody next week in the great city of #Antwerpen. 😊

Now, If you haven't already, check @openfsharp in San Francisco: 27-27sept. 💙

Hey #javascript friends! Maybe you don't know the Fable project? It's about using F#, a functional language for your next #js project. Come to meet us in #Antwerpen next week. We'll be happy to show you everything at #FableConf. Check fable.io. cc @JavaScriptDaily

Have you ever wondered why Fable's been elected tech-of -the-year 2029? And why everybody's been speaking 🇪🇸in IT since 2022? And why French 🧀replaced ☕️in 2025?

Then come hear functional predictions by @alfonsogcnunez and @thewhitetigle: 🥁Fable 2029🥁

#FableConf #fsharp

📡Type-safe Client & Server Communication📡

Are you struggling with type safe routing? 😭 Worry no more! 😊During his lightning talk, @BrettRowberry will casually enlighten you with the joys of Fable.Remoting. 🥰

Check the schedule: fable.io/fableconf/#age… #fsharp #FableConf

🏄‍♀️Intensive browser computation and Fable🏄‍♂️

In this lightning talk, Coling Gravill, @CGravill, will explain how to run computationally intensive code in the browser: F# in Web Workers that use external C++ via WebAssembly!

More info: fable.io/fableconf/#age… #fsharp #FableConf

🌖Fable Breakout: Beyond Elmish🌖

The sky. The limit!
Fable is much more than SPAs and Elmish. Let Joerg Beekmann, @jbeeko, show you how true this is through several real-life samples: CloudFlare Workers, ComosDB, etc.. At #FableConf

More info: fable.io/fableconf/#age… #fsharp

📸Mastering Server Side Rendering📸

Single Page Applications are great but sometimes you need faster solutions. Enter server side page rendering with F# and .NET, which will be presented by Steffen Forkmann @sforkmann at #FableConf.

More info: fable.io/fableconf/#age… #fsharp

📱Web Remote Control 🧙‍♂️

At #FableConf, @theimowski will share with us his lastest breakthroughs with #javascript, Fable & Elmish: establish Remote Control & Takeover connections directly from a browser!

To hear his story, wait no more, join us: fable.io/fableconf/#age… #fsharp

⚡️Building F# Tooling⚡️

Meet Krzysztof Cieślak, @k_cieslak, best known for his huge involvement in F#/#OSS through projects like the @IonideProject.

For his 3rd year at #FableConf 🥳, Krzysztof will share his vision on F# tooling.

More info: fable.io/fableconf/#age… #fsharp

✨Functional Adventures on High-Performance Computer Graphics✨

Interested in Computer Graphics? Then come at #FableConf to hear the story of Georg Haaser, who used Fable and F# to generate shaders, from the browser.

More info: fable.io/fableconf/#age… #fsharp

🤠Too Old for JavaScript, Still Young for Elmish🤠

Need to build a nice web UI in no time but you don't know css, javascript or react? Then hear how Fable helped Vagif Abilov, @ooobject, a backend dev into frontend land.

More info: fable.io/fableconf/#age… #fsharp #FableConf

⚙️A Journey into the Compiler and Tooling⚙️

Want to know a little bit more about Fable inner workings? Learn more about fable-loader, fable-splitter? And maybe join the compiler party?
Then check out @verdonckflorian's talk at #FableConf: fable.io/fableconf/#age… #fsharp

🧙‍♂️Let's talk Magic with @dbrattli! 🧙‍♂️

Dag will tell us all about the use of 💫Elmish Streams 💫 to combine #reactive programming with #elm famous Model View Update to enable powerful event handling in your web apps!

More info here: fable.io/fableconf/#age… #fsharp #FableConf

Do you want to know more about publishing & maintaining Open Source libs? Then come to #FableConf in Antwerp, 6/7 September, to hear from @zaid_ajaj and the Joys of #OSS. More info here: fable.io/fableconf/#age… … #fsharp

There's also space for poetry at #FableConf. Please enjoy this haiku by @thewhitetigle :)

Last year @evelgab talked about using #fsharp and Fable for #datascience youtube.com/watch?v=YpX5yh… Discover more at this year's #FableConf in Antwerp! fable.io/fableconf/

Thanks to @zaid_ajaj the Fable.JsonProvider already accepts HTTP urls as a parameter!

github.com/fable-compiler…

Using a "tweaked" version of Fable to run FShade in the browser and generate shaders in runtime from F# code, by Georg Haaser: youtube.com/watch?v=s5rO0R…

We just announced next #FableConf will happen in beautiful Antwerp, Belgium on 6/7 September. Early bird tickets will be available soon, stay tuned! fable.io/fableconf/

🤯@orlandotheegg github.com/Fable-Fauna/Fa…

And btw, now you can use @zaid_ajaj Fable.SimpleHttp in the REPL: fable.io/repl/#?code=PY…

The REPL load times have been improved and also now you can save your work directly to a Github Gist. Thanks a lot to @DiEsmerio for contributing this feature!

Factorial for different numeric types (including Bigint and decimal) in Fable REPL fable.io/repl/#?code=PY…

Fable.React 5.0.0-alpha-001 is released with "memoBuilder" for compatibility with new "React.memo". Check the comment docs for usage. Thanks a lot to @virtualblackfox. Now you can apply the advice from his talk at #FableConf youtube.com/watch?v=9VJoaN…

You can see this talk... 1/2 youtube.com/watch?v=C3mh-Y…

Now you can play with the Tour of #fsharp by @_cartermp in the Fable REPL! fable.io/repl/

New Fable version released with several issues solved including a fix to show non-mangled variable names in browser devtools with source maps github.com/fable-compiler…

"Scaling Elmish Applications" by @zaid_ajaj shows you the patterns to combine components with ease in large Elmish apps youtube.com/watch?v=-Oc4xJ…

"Offline Progressive Web Apps with PouchDB" by @thewhitetigle teaches how to implement one of the new paradigms in web apps using Fable and PouchDB: offline capabilities and automatic sync of local and remote databases youtube.com/watch?v=C3mh-Y…