The php6 file extension is used by Microsoft Expression Web for PHP script files.
PHP6 file extension - Microsoft Expression Web php script
What is php6 file? How to open php6 files?
File type specification:
The php6 files are found with Microsoft Expression Web a software developed by Microsoft for Windows system that allows users to create web apps.
The php6 file contains script written in popular PHP version 6 and created in Microsoft Expression Web.
Common file extension used for PHP scripts is .php.
This php6 file type entry was marked as obsolete and no longer supported file format.
This type of file is no longer actively used and is most likely obsolete. This is typically the case for system files in old operating systems, file types from long discontinued software, or previous versions of certain file types (like documents, projects etc.) that were replaced in higher versions of their original programs.