The new project format in v5.00 and greater supports packs which contain versioned device information. Packs can be found under:
<MPLAB X IDE install directory>\v5.xx\packs
Managing Projects
Projects created in or updated to v5.00 or greater are not backward compatible to v4.xx.
When you open a project created prior to v5.00, a message displays, announcing that it will upgrade the project to the current project version.
If you upgraded a project to v5.xx but need to revert a project back to v4.xx, install the plugin in MPLAB X IDE found under Tools>Plugins>Available Plugins>Save As v4.xx Project. Once that plugin is installed, you can save your project in the older version by selecting Tools>Embedded>Save as MPLAB X v4.xx Project.
About Device Packs
Previously (v4.20 and earlier versions), supported device (*PIC) files that were built into each MPLAB X IDE version. You could not update the devices supported in this version; you had to wait until the next MPLAB X IDE version for device support.
Now (v5.00 and latest versions), the device files are grouped into versioned device family packs. Although each MPLAB X IDE version comes with device packs, you may upgrade the device pack version to include new devices, new device feature support, or device bug fix support.
For more information on device packs, see: