What is F# written in?
F# is a Microsoft programming language, first released in 2005.
Implementation
| Layer | Written in | Notes |
|---|---|---|
| Bootstrap | OCaml (since 2005) | F# initial compiler written in OCaml before self-hosting |
| Compiler | F# (since 2010) | F# compiler became self-hosting |
Self-hosting
F# is a self-hosting language: its compiler is written in F# itself. Self-hosting means the compiler can compile its own source code, which is a milestone in a language's maturity. New versions of the compiler are built using an older version of the same compiler, a process called bootstrapping.
Self-hosting also acts as a practical stress test: if a language can compile its own compiler, most core language features have been validated in a complex, real-world workload. See what is compiler bootstrapping for a full explanation.
Explore in the Graph
See F#'s full lineage, including all implementation and influence relationships, in the interactive graph.
Open Interactive Graph →Or view the F# language page for the complete record.