Files with opo file suffix are related to the Psion OPL object format.
OPO file extension - Psion OPL object
What is opo file? How to open opo files?
File type specification:
The opo file extension is used for one of the data formats used in older Psion devices.
Psion is a designer and manufacturer of mobile handheld computers for commercial and industrial applications.
This opo 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.