In which language is F#'s compiler written?

In which language is F#'s compiler written?

I've heard that F#'s compiler is written in F# :)

(each next version of F# compiler is written on its previous version)

But:

1. Can't google if it's true.

2. If it'开发者_开发百科s true, in which language is the first version of the F# compiler written?

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The F# compiler is written in F#. The source code is available.

It was originally bootstrapped years ago using OCaml, I believe (and perhaps a little C++ as well). (There is still a non-trivial subset of F# that cross-compiles with OCaml, though the F# compiler source base has long since diverged from that.)

The current implementation always uses an LKG (last-known-good) set of binaries (.NET DLLs and EXEs) to bootstrap itself when building from source.