What is "freetype"

FreeType is a popular software development library, used to render text on to bitmaps and provides support for other font-related operations. The FreeType font rasterization engine is free and open source software with the source code dual-licensed under a BSD-like license and the GPL. FreeType supports a number of font formats, including TrueType, Type 1, and OpenType and "is designed to be small, efficient, highly customizable, and portable while capable of producing high-quality output (glyph images)."