Enhanced Metafile (EMF) is a vector graphics format native to 32-bit versions of Microsoft Windows. It is the successor to Windows Metafile (WMF).
There is an extension of the format, named Enhanced Metafile Format Plus Extensions (EMF+).
The .emz filename extension is reportedly used for gzip-compressed EMF files.
Though EMF is very similar in concept to WMF, the format itself is quite different, and completely incompatible. It has a different record structure, and different command opcodes.
EMF files begin with bytes
01 00 00 00 (representing record type EMR_HEADER), and have ASCII "
EMF" (with the leading space) at file offset 40.
EMF+ files are EMF files with the following characteristics. Let n be the 32-bit integer at offset 4. At offset n is the 32-bit integer 0x00000046 (representing record type EMR_COMMENT). At offset n+12 is the ASCII string "