object_manipulation vs GraspIt vs OpenRave

edit

All the libraries you mention are being actively worked on and maintained. Each library has its own focus and set of things it does well. Depending on your particular use case, you should look for whether the library does everything you want.

What kind of objects are you doing grasp planning for? object_manipulation can do grasp planning for point clouds, GraspIt does it for meshes, and so on. The motion planning stacks in ROS offer a complete pipeline from planning to execution. OpenRave can do fast IK for most arms. Depending on what you want, one or the other library might be more suitable for you.