You can make it possible to mount a MAC HFS+ as Read and Write in Ubuntu Linux.
sudo apt-get install hfsplus
Then, use the -o force option to force the drive to mount:
sudo mount -o force /dev/sdX /your/mount/point
If the drive has been mounted automatically (as it should be on a desktop system like Ubuntu), you can enable remounting as writeable by:
sudo mount -o remount,force /mount/point
sudo mount -o remount,force /dev/sdx
Use mount -l to find which devices are already mounted on which mount points.
I used this to save data off of the mac hard drive