The main author of FreeType was David Turner, who created the library in 1996 to render TrueType fonts, including an interpreter for handling TrueType bytecode. It was originally written in the Pascal programming language. In 1997, Robert Wilhelm ported it to C, and Werner Lemberg joined the team. Originally, the C and Pascal versions were developed in parallel, however, development of the Pascal version stopped in 2000.
Using FreeType 1, as this original version is called today, some programs were written which then had some impact, for example FreeType/2, a better TrueType font driver for the OS/2 operating system, or ttf2pk, a converter from TrueType fonts to TeX's PK bitmap format (this program, while updated to use FreeType 2, is still part of TeXLive).
Robert Wilhelm stopped working on FreeType in 2000.
For historical reasons you can find here links to the documentation of FreeType 1. Note that those pages are no longer maintained.
After several beta releases, version 2.0 of FreeType was released in 2000, providing a complete rewrite to make it modular. To distinguish it from FreeType 1, it was then called FreeType 2 (which is no longer necessary today). Most important new features were the support of multiple font formats, in particular PostScript fonts (together with hinting engine), a much improved rendering backend for gray-level images, and a module for caching glyphs images and glyph metrics. Later versions added support for even more font formats and LCD rendering modes.
In the year 1999 we were informed by Apple Inc. that FreeType was infringing patents related to TrueType hinting (see here for more). As a consequence, we disabled the bytecode interpreter completely by default. Later on we were able to refine this radical cut by disabling only the patented instructions, handling more than 95% of the other instructions just fine and circumventing problems with the remaining 5% to a certain extent. Another consequence was the invention of the auto-hinter which needs no hints at all (you can find here an early scholarly paper). Today, the TrueType patents have expired.
Around 2004 it was decided to restrict FreeType to a single target: Creating (rasterized) glyph images. Attempts to handle OpenType layout features and text shaping were abandoned since this could be handled much better with a separate library on top of FreeType (cf. ICU or Harfbuzz).
In 2009, the source code repository has been migrated from CVS to git, and David Turner stopped active development on FreeType. Since then the only maintainer is Werner Lemberg, with the help of others who contribute fixes and improvements.
Last update: 18-Jan-2019