TrueType (TTF) is a standard outline font format developed by Apple and Microsoft in the late 1980s. It allows for high-quality font scaling on computer screens and printers by using mathematical curves to define character shapes. TTF is the most common format for installing fonts on both Windows and macOS systems and supports a wide range of international characters. Sample TTF files are used to test text rendering engines and font management utilities. Developers use them to verify that glyphs are correctly rasterized at different point sizes and resolutions. They are also used to test font embedding in documents (like PDFs) and to ensure compatibility with legacy operating systems and software.