- Iosevka is an open-source font family made for code, terminals, and technical documentation. A monospaced font is one where every character has the same cell width. The source mainly cites coding as its use.
- According to the source, the width of one character in the default monospaced font is exactly 1/2em (em is the reference unit for measuring character size). The source claims this allows more columns in the same screen width, and this is the creator's explanation.
- There are separate Term and Fixed families for terminal programs. The source says terminals require stricter font compatibility. It states that the Fixed family turns off ligatures, which combine several symbols into one glyph, to improve compatibility in some environments.
- Aile and Etoile are font families prepared for document writing. The source explains that they slightly vary character widths, widening w and m a little and narrowing i and l. The source states that this font supports 248 languages.
O: Developers who want to change their code editor font can switch to the Iosevka Term family and then compare, by opening the same few lines of code, whether more columns fit on one screen.
X: The space-efficiency claim in the original is the creator's own description, so the difference you actually see on screen may vary depending on the editor and resolution.