I'm looking back at some old MS security bulletin for distribution to new clients and when I look at downloads for the last set of MS ActiveX killbits, KB article here, under each platform I see links with the term IDX. For instance there will be an entry that says "For Windows 7 for 32-bit versions" and then one a few rows down that says "For Windows 7 IDX for 32-bit versions".
What's the difference between the two? I understand from a little digging that idx is one of the field names for the database that ActiveX controls are stored in, but that's not really helpful.
I believe IDX stands for Internal Developer release, where X stands for Client or Server.