I've been playing around with Bezier curves and elliptical arcs for my on-going CNC plotter project. Instead of just using g-code commands which are standard on most CNC machines, I decided to support SVG path commands. This means supporting the linear moveTo(M, m) and lineTo(L, l) as well as curve(C, c, S, s -- Q, q, T, t)/arc(A, a) commands.
Here are a few articles to get you up to speed if you're unfamiliar with the SVG path commands:
SVG Basics—Creating Paths With Line Commands by Steven Bradley
SVG Basics—Creating Paths With Curve Commands by Steven Bradley
tl;dr, I just need a library