Gforth and pForth [0] are the usual Free and Open Source go-to Forths. Gforth is quite good at pointing out silly mistakes in your code. Unfortunately Gforth doesn't have great Windows support, and neither of them have very strong FFI.

There are a number of proprietary payware Forths for desktop/server: vfxForth, [1] SwiftForth, [2] and iForth. [3]

There are also various Forths for all sorts of embedded platforms, many of them FOSS.

[0] https://github.com/philburk/pforth

[1] https://vfxforth.com/

[2] https://www.forth.com/swiftforth/

[3] https://iforth.nl/