I merged initial experimental support into LibreCAD yesterday.
Some basic features of Offset still need to be implemented:
1, loop, self-intersection awareness;
2, Generate a spline fit, if the offset envelop is not in simple entities(straight line, arc, and ellipse);
3, More options to initiate Offset.
If you find a bug in LibreCAD, or simply want LibreCAD to do more, please file a feature request/bug report at our sourceforge trackers:
The LibreCAD team