Calibri features subtly rounded stems and corners that are visible at larger sizes. Its sloped form is a "true italic" with handwriting influences, which are not unusual in modern sans-serif typefaces. The typeface includes characters from Latin, Latin extended, Greek and Cyrillic scripts. Calibri makes extensive use of sophisticated OpenType formatting; it features a range of ligatures as well as lining and text figures, indices up to 20, and an alternatef and g accessible by enabling the fourth and fifth stylistic sets. Some features in Calibri remain unsupported by Office, including true small caps, all-caps spacing, superscript and subscript glyphs and the ability to create arbitrary fractions; these may be accessed using programs such as Adobe InDesign. One potential source of confusion in Calibri is a visible homoglyph, a pair of easily confused characters: the lowercase letter L and the uppercase letter i of the Latin script are effectively indistinguishable; this is true of many other common fonts, however. The design has clear similarities to de Groot's famous and much more extensive commercial family TheSans, although this has straight ends rather than rounding. a Hebrew alphabet version is in development. De Groot has also said in 2016 that he would like if possible to add Bulgarian alphabet variant letterforms at a later date.
Availability
Calibri is the default typeface of Microsoft Office and much other Microsoft software. Joe Friend, a program manager on Word for Office 2007's release, explained that the decision to switch to Calibri was caused by a desire to make the default font one optimised towards onscreen display: "We believed that more and more documents would never be printed but would solely be consumed on a digital device", and to achieve a "modern look". Because of the long development of Windows Vista, Calibri's development – from 2002 to 2005 – occurred several years before the release of that OS. It was first presented in a 2005 beta of Windows Vista, then codenamed Longhorn, and first became available for use with the Beta 2 version of Office 2007, released on May 23, 2006. Calibri and the rest of the ClearType Font Collection were finally released to the general public on January 30, 2007, since when it has been released with most Microsoft software environments. Calibri is also distributed with Microsoft Excel Viewer, Microsoft PowerPoint Viewer, the Microsoft Office Compatibility Pack for Microsoft Windows and the Open XMLFile Format Converter for Mac. For use in other operating systems, such as cross-platform web use, Calibri is licensed by Ascender Corporation and its parent company Monotype Imaging. The font Calibri Light was introduced in Microsoft Windows 8 and added to Windows 7 and Server 2008 as part of a software update. From Microsoft Word 2013 onwards, Calibri and Calibri Light are the default fonts for body text and headings respectively. Calibri Light is also a default font for headings in Powerpoint. In 2013, due to Calibri's widespread use in Microsoft Office documents, Google released a freely-licensed font called Carlito, which is metric-compatible to Calibri, as part of ChromeOS. Because Carlito has the same font metrics as Calibri, ChromeOS users can correctly display and print a document designed in Calibri without disrupting layout. Carlito’s glyph shapes are based on the prior open-source typeface Lato, without de Groot's involvement.
Because of Calibri's position as the default font in Office, many cases have been reported in which documents were shown to be forged thanks to a purported creation date before Calibri was available to the general public.
FontGate
In 2017, the font came to public attention as evidence in the Pakistani government-related "Panama Papers" case, in which a document supposedly signed in February 2006 was found to be typed up in Calibri. De Groot said that there was "really zero chance" that the document was genuine.
