The SDF (Standard Distribution Format) font format is a standardized font file format that was developed by IBM and Adobe Systems. The format is used for scalable fonts that can be used on a variety of platforms, including desktops, mobile devices, and printers. SDF fonts are typically composed of vector graphics that are easy to resize without losing quality, making them ideal for use in digital publishing and graphic design. SDF fonts are widely supported by many different software applications and operating systems, making them a popular choice for font designers and users alike.