We compute the fundamental group of the complement of each irreducible sextic of weight eight or nine (in a sense, the largest groups for irreducible sextics), as well as of 169 of their derivatives (both of and not of torus type). We also give a detailed geometric description of sextics of weight eight and nine and of their moduli spaces and compute their Alexander modules; the latter are shown to be free over an appropriate ring.
Alex DEGTYAREV. "Irreducible plane sextics with large fundamental groups." J. Math. Soc. Japan 61 (4) 1131 - 1169, October, 2009. https://doi.org/10.2969/jmsj/06141131