No plans AT ALL to make IH4 backwards compatible.. Shop owners will need to upgrade to Zen Cart v1.5 to use IH4. Only reason to consider making an add-on backwards compatible is if we were fixing bugs currently existing..
There are a few new features/improvements in IH4:
- Seriously EASY auto installer and equally easy uninstaller. (retains backups of "pre IH3" core files for easy rollback in the event of an uninstall)
- Improved language support (removed all hard-coded text and moved into proper language files)
- Enhancements to help further reduce errors from invalid file uploads
- Use IH4 Image Manager even if you choose NOT to use any of the image caching or other management features.
Given the free time being invested by ALL the volunteers involved in this upgrade effort, it is not worth making any serious effort to update IH3 to include these same features/enhancements -- even for the sake of backwards compatibility.
IH3 is stable and works for Zen Cart v1.3.9 stores.. Therefore, the enhancements in IH4 will be available only if you upgrade to Zen Cart v1.5.
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