If you downloaded your designs from an online vendor in the format that your embroidery machine is compatible with, example Brother .PES, Viking .VP3, etc., then you can transfer that design onto your embroidery machine's USB stick directly from your Mac, and then from the USB to your embroidery machine. However, without software, it stitches exactly like it came from the vendor and editing, such as sizing will have to be done with capabilities that your embroidery machine allows, which can be very limited.