Scheme Compilers:

* Gambit-C 3.0 for MS-DOS (https://gambitscheme.org/3.0/gc30-dj.zip)

* MIT-Scheme 7.3 for DOS: (https://groups.csail.mit.edu/mac/ftpdir/scheme-7.3/pc/)

Both need a 386+.

* PC-Scheme/Geneva (https://www.cs.cmu.edu/afs/cs/project/ai-repository/ai/lang/...) Bytecode compiler, runs on 8086+, can use up to 2MB of EMS memory.