The Forth Scientific Library is included in
Some of the FSL routines have been ported to Krishna Myneni's kForth,
which does not have a separate floating-point stack.
Work on improved testing of FSL files can be found at this location.
Some scientific forth routines by Julian Noble, including his Fortran-to-Forth converter,
are in this collection .
A (not completely up-to-date) version of the FSL is included in Andreas Kochenburger's MinForth.
David N. Williams has a collection of complex number implementations and tests.
Links from that page lead to other material related to Forth numerical programming.