The Microchip MPLabX IDE, IPE and XC8 packages need additional 32-bit libraries and so their installation is slightly more involved than just running the installer scripts.
The details:
sudo apt-get install libc6:i386 libx11-6:i386 libxext6:i386 libstdc++6:i386 libexpat1:i386 wget http://ww1.microchip.com/downloads/en/DeviceDoc/MPLABX-v2.10-linux-installer.run wget http://ww1.microchip.com/downloads/en/DeviceDoc/xc8-v1.32-linux-installer.run.tar tar xvf xc8-v1.32-linux-installer.run.tar rm xc8-v1.32-linux-installer.run.tar chmod +x MPLABX-v2.10-linux-installer.run xc8-v1.32-linux.run sudo ./MPLABX-v2.10-linux-installer.run --mode text sudo ./xc8-v1.32-linux.run --mode text
In my case it was not necessary to reboot.
Also see:
http://www.microchip.com/pagehandler/en-us/family/mplabx/
http://microchip.wikidot.com/install:mplabx-lin64