Metrically Compatible Fonts
Metrically Compatible Fonts are fonts that have the same cap height, x-height, ascender height, descender height. That means, you can change the font on a web page without changing font size and the layout and effective font size remains the same.
[see Meaning of Font Size]
They are usually automatically substituted by the operating system if one of these is not available.
Metrically Compatible Fonts are created mostly as clones to avoid copyright.
Arial compatible (sans-serif)
Helvetica- Year 1957. On Mac since 1980s.
Arial- Year 1992. Microsoft clone, since Windows 3.1.
Liberation Sans- 2007. Linux.
Arimo- Google, ~2013
Calibri compatible (sans-serif)
Calibri- 2007. Sans-serif. Arial sequel. Replaced Arial as the default in PowerPoint, Excel, Outlook, WordPad. Replaced Times New Roman in Microsoft Office.
Carlito- Google. 2013
Times New Roman compatible (serif)
Times New Roman- Year 1932. On Mac/Windows since 1990s.
Liberation Serif- Linux. 2007
Tinos- Google. 2013
Cambria compatible (serif)
Cambria- Serif. Microsoft Windows and Office, 2007.
Caladea- Google. 2013
Consolas compatible (monospace)
Consolas- Year 2007. Monospace. Microsoft's replacement for Courier New.
Inconsolata- Year 2006. Monospace. Linux.
Courier New compatible (monospace)
Courier New- 1970s
Liberation Mono- Linux. 2007
Cousine- Google, 2013
DejaVu Sans Mono compatible (monospace)
Bitstream Vera Sans Mono- Year 2001. Monospace. Open source.
Menlo- Year created: 2009. Monospace. Based on open source DejaVu Sans Mono.
DejaVu Sans Mono- Year created: 2004. Monospace. Based on open source DejaVu Sans Mono.