My field of research is in the area known as Hopf-Galois Theory which is a generalization of the classical Galois theory for fields.
In this setting one can consider a separable extension (which may not be Galois in the usual sense) as being Hopf-Galois where instead of a group acting on the extension, one has a Hopf algebra which acts. Note that a classical Galois extension L/K with G=Gal(L/K) is also Hopf-Galois in a very natural way under the action of the Hopf algebra H=K[G].
The work of Greither and Pareigis showed how to classify and enumerate such extensions by looking at certain permutation groups.
In broad terms Hopf-Galois theory can be viewed as an aspect of Galois Module Theory.
[2] Classification of the Hopf Galois Structures on Prime Power Radical Extensions, J. Algebra, 207 (1998), 525-546
[3] (with D. Replogle) Computation of Several Cyclotomic Swan Subgroups, Math. Comp., 71 (2002),343-348
[4] (with D. Replogle) Cyclotomic Swan Subgroups and Primitive Roots, Finite Fields and Their Applications,11 (2005),655-666
[5] Groups of Order 4p, Twisted Wreath Products and Hopf-Galois Theory J. Algebra, 314 (2007), 42-74.