Windows Metafile (WMF) and Enhanced MetaFile (EMF) are 2 linked image formats developed by Microsoft since the 1990s. Enhanced MetaFile is essentially an updated version of WMF which makes it 32 bit and addresses some other issues. Unlike most other image formats, it is a Vector file format. While it can contain bitmap data, it mainly consists of shapes, lines and other Vector shapes. So it can be scaled or output to different devices such as printers which can draw the contents in much higher definition. In many ways, it is similar to PostScript, which was the predecessor to the PDF File Format.
EMF/WMF formats been developed and extensively supported by Microsoft, and it is the native Vector File format for Microsoft Office applications so many Companies have lots of WMF/EMF files. However, it was not extensively adopted by other platforms and most Browsers.
EMF/WMF file formats are similar to SVG, which is widely supported by browsers because it is a part of HTML5.
We have been seeking to add the widest range of Image File formats to our JDeli Java Image library, which allows Java developers to read and write a wide range of Image formats. With WMF/EMF we decided to not only support the ability to read both as an Image, but also to convert the WMF/EMF files directly to SVG, so they can then be used directly on the Internet. This allows developers to retain all the flexibility and benefits of the original, scaleable files. We hope you like the results!