In this page you can find the most recent versions of Factory I/O for download. The recommend way to setup Factory I/O is to use the installer. However, you may choose to download the portable version (zip archive) which allows to run Factory I/O without installing it. Note that the portable version does not include dependencies required by interface board drivers (Advantech) and OPC drivers.
Note: versions below 2.4.0 are not available for download since they are not compatible with current licensing system.