Embird is described as 'Software for designs (patterns) management, digitizing and lettering. 70+ embroidery, cross stitch and quilting formats for home and industrial machines'. There are four alternatives to Embird for Windows, Mac, Linux, Inkscape and Raspberry Pi. The best alternative is Embroidermodder, which is both free and Open Source. Other great apps like Embird are Ink/Stitch (Free, Open Source), SewArt Embroidery Digitizer (Paid) and CAD Assyst (Paid).
Embroidermodder is a free machine embroidery software program which allows editing, scaling, and translating sewing machine embroidery files to a variety of formats. It allows the user to add custom modifications to their embroidery designs.