An ixx file extension is associated with the Modula-3 Linker and used for its information files. Probably obsolete.
IXX file extension - Modula-3 Linker information
What is ixx file? How to open ixx files?
File type specification:
The ixx file extension is related to the Modula-3 Linker.
Modula-3 is a programming language conceived as a successor to an upgraded version of Modula-2. While it has been influential in research circles (influencing the designs of languages such as Java and C#), it has not been adopted widely in industry.
The ixx file contains information.
This ixx 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.