Racket has support for OS-level threads via places.
Racket can create a single binary with
Racket can be run on ARM.
Racket implementation is based on a bytecode compiler and VM.
LambdaNative is a cross-platform development environment written in Scheme, supporting Android, iOS, BlackBerry 10, OS X, Linux, Windows, OpenBSD, NetBSD, FreeBSD and OpenWrt. It is a wrapper and abstraction over Gambit Scheme. It does not support multi-core threading.
Racket is intended for Language-Oriented Programming.
The original professor (Matthias Felleisen) and grad students were solid PL people who were interested in making CS education more accessible