Everywhere you look, programming languages are gaining functional features. The problem is that it's not the individual features that make functional programmers happy, it's the way that your approach to writing software and the features work together to help you write simple code to solve interesting problems. This book will help you to discover why F# is such a popular language with those who have spent time learning its secrets. 

This book started life as a series of blog posts I wrote for the Trustbit website (https://trustbit.tech/blog). The sum of the content is the core of what a developer needs to know to be able to work on one of their F# Line of Business codebases. I have improved and extended the content, upgraded the code to F# 5, and ensured that the code would run in VS Code with the free ionide extension.

This book is FREE. If someone feels that they want to pay money for it, the author's royalties (80%) will continue to go to the F# Software Foundation.

You can report issues with this book to https://github.com/ijrussell/essential-fsharp.