Four easy steps for installing F# on Ubuntu Linux
First: Configure Ubuntu so it recognizes the Mono repository, an open source Linux implementation of .NET Framework.
Mono on Linux before 3.12 by default didn't trust any SSL certificates so you got errors when accessing HTTPS resources…www.mono-project.com
Second: Install F#, this step first installs Mono and then F# proper, so it takes a few minutes, have a little patience :-)
When being used as .NET language, F# requires a .NET runtime. On Linux this runtime is Mono or .NET Core. Most Linux…fsharp.org
You could start writing F# code already albeit using the command-line tools so…
Third: Install Visual Studio Code, a developer’s open source editor, you download a .deb package, and then double-click it.
Visual Studio Code is a code editor redefined and optimized for building and debugging modern web and cloud…code.visualstudio.com
Fourth (and last): Launch Visual Studio Code (writing code at a command line will do), then install the ionide plug-ins: F#, Fake (a build utility, like C make, but written in F# itself), and Paket (a packet manager, like maven, npm, or nuget, equally written in F#).
And you’re all set! You can now experience coding in a functional language on a lightweight open source environment :-)