Sun's patchcheck Perl script, requires this data file.
Microsoft's redistribution of the hfnetchk executable
RedHat Network, and Ximian Red Carpet
[Update: 15 July 2002] Microsoft Software Update Services
Sun has updated their offering with PatchManager and PatchPro: http://sunsolve.sun.com/patches/
A user pointed out a failure in Apple's SoftwareUpdate program [CVE CAN-2002-0676], for which Apple issued a new version.
Just a list: