application/x-msdownload

The de facto label for .exe and .dll files — Windows Portable Executable binaries — that Apache's mime tables spread across the web. Every PE file still opens with MZ, the initials of Microsoft's Mark Zbikowski, because a 1980s MS-DOS stub lives at the front of every modern Windows binary; the pointer at offset 0x3c locates the real PE\0\0 header somewhere behind it. The type itself was never registered: IANA's blessed name is application/vnd.microsoft.portable-executable, which almost nobody sends. Serving executables? Most servers just use application/octet-stream and let the filename do the talking.

mime-db maps .exe, .dll, .com, .bat, and .msi here — only .exe and .dll are actually PE binaries.

Defined by Microsoft PE Format. Registry facts from the IANA media-types registry via mime-db.