CoreWin 2.2 is Chip Wendell's feature packed Mars for Windows.

pMars - C source for the official Redcode simulator of pMars-SDL is a Windows binary provided by Joonas Pihlaja.

pyCorewar is Jens Gutzeit's Python Redcode simulator.

fMars (fast Mars) is Michal Janeczek's Redcode simulator.

Martin Ankerl is the author of QMars (Quicker Mars), exMARS and Exhaust-ma. [archived locally]

A.R.E.S. is a simulator for Windows with extensions allowing stacks, absolute addressing and console i/o. Includes an operating system written in Redcode.

nMars by Pavel Šavara

Phil Knight has written two scheduling utilities for Windows, CoreWar Tournament and TestWarrior. [archived locally]