There is only one file type that uses the .ONTX extension:
theWord Encrypted Bible Text Module
File used by theWord free Bible software; stores a translation of the Bible in an encrypted format; differs from an .ONT file, which does not use encryption; allows users and third-party vendors to protect their version of the Bible.
ONTX files are often distributed as ".ontx.exe" executable files that self-install the Bible when run.
Updated: September 5, 2012