An ixr file extension is related to the Index+ report definition file format.
IXR file extension - Index+ report definition data
What is ixr file? How to open ixr files?
File type specification:
The ixr file extension is associated Index+, information retrieval database system written in C and C++.
The ixr file report definition data.
The Index+ software seems to be obsolete product without any support from developer.
This ixr 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.