# Installing SML/NJ under Cygwin

version 110.99.9, November 4, 2025

## Introduction

These instructions are for installing Standard ML of New Jersey (SML/NJ) in the Cygwin 32-bit environment.

### Building SML/NJ as a Unix application

It is recommended that you install SML/NJ in a volume that has been mounted in binmode.

Otherwise, just following the standard instructions for installing on Unix/Linux systems.

### Building SML/NJ as a Windows application

It is possible to build SML/NJ using the Windows version of the runtime system under Cygwin. To do so, you must set the `SMLNJ_WINDOWS_RUNTIME` shell variable:

    % export SMLNJ_WINDOWS_RUNTIME
    % SMLNJ_WINDOWS_RUNTIME=1
    % config/install.sh