Fundamental groups of complements of plane curves and symplectic   invariants
  Introducing the notion of stabilized fundamental group for the complement of a branch curve in $CP^2$, we define effectively computable invariants of symplectic 4-manifolds that generalize those previously introduced by Moishezon and Teicher for complex projective surfaces. Moreover, we study the structure of these invariants and formulate conjectures supported by calculations on new examples. 
D. Auroux, S. K. Donaldson, L. Katzarkov, M. Yotov