TrueType is an outline font standard originally developed by Apple Computer in the late 1980s as a competitor to Adobe's Type 1 fonts used in PostScript. The primary strength of TrueType is that it offers font developers a high degree of control over precisely how their fonts are displayed, right down to particular pixels, at various font heights. On the Macintosh, fonts were drawn from hand-tuned font files that specified individual pixel locations for a font at a particular size. If the user wanted to see a font at another size, the Font Manager found the closest match and applied a basic scaling algorithm. When scaled to large sizes the effect was comical– since these fonts were bitmapped, they would scale the same way any raster graphics image does, becoming blocky. In contrast, printer fonts for the popular Apple LaserWriter were based on PostScript Type 1 outlines, resulting in excellent output at any size. Although Adobe provided the Adobe Type Manager software to use the same fonts on-screen, the software was fairly expensive. Nevertheless it became a de facto standard for anyone involved in desktop publishing, to the point where Apple wanted to have a similar system built-in. Making matters difficult was the fact that Type 1 fonts were encrypted, and Adobe made a considerable amount of their income from licensing the format to interested parties. One huge drawback of the TrueType system is that it could not use Type 1 fonts on-screen. However this meant that the system was in fact not used by the very people it was intended to help, desktop publishing software users. They had already invested considerable money in commercial Type 1 fonts, which they were not interested in replacing, and therefore had to continue using Type Manager. Adding to the problem was that there were very few fonts available in TrueType format, so even if one wanted to start fresh there was no real way to do so.
Microsoft had built TrueType into the Windows operating system in the year 1991. In partnership with their contractors Monotype, Microsoft spent much effort creating a set of high quality TrueType fonts that were compatible with the main fonts being bundled with PostScript equipment at the time. This included the fonts that are standard with Windows to this day like Times New Roman, Arial and Courier New. Microsoft and Monotype technicians used TrueType's hinting technology to ensure that these fonts did not suffer from the problem of illegibility at low resolutions which had previously forced the use of bitmapped fonts for screen display. Subsequent advances in technology have introduced first anti-aliasing, which smooths the edges of fonts at the expense of a slight blurring, and more recently subpixel rendering, which exploits the pixel structure of TFT based displays to increase the apparent resolution of text. As Microsoft has marketed these technologies particularly heavily, they are now widely used on all platforms.
TrueType is nowadays the most common format for fonts on today's Mac OS X and Windows XP, although both also include native support for Adobe's Type 1 format and the OpenType extension to TrueType. While many of the fonts provided with the system are now in the OpenType format, most free or inexpensive third-party fonts use plain TrueType.