And also here:
It also brings the Windows code up to speed.
Full list of changes from 0.27.5:
150520 Released 0.28.0.
150513 Numerous updates to support the madness that is Windows.
150501 Fix from Vincent Bernat: segfault when not using SSL.
150427 DSR support using Netmap on FreeBSD.
Unbroke DSR on Linux.
150424 Replaced all calls to perror with debug(…, strerror(errno);
Updated penlog and penlogd to use diag.[ch].
150422 More refactoring: broke out conn.[ch], client.[ch], server.[ch],
Made a hash index such that the load balancer may balance load.
150420 Broke out Windows code from pen.c into windows.c. Added windows.h.
150419 Broke out public definitions for dsr into dsr.h.
Broke out memory management into memory.[ch].
Broke out dignostic and logging functions into diag.[ch].
Broke out settings into settings.[ch].
Broke out access lists into acl.[ch].
Broke out event initialization into event.[ch].
Added pen_epoll.h, pen_kqueue.h, pen_poll.h, pen_select.h.
Broke out pen_aton et al into netconv.[ch].
150416 Added dsr.c