Apple Menlo vs Iosevka

Equally well readable as Bitstream Vera/DejaVu Sans Mono, but with slashed zeros (aids with legibility).

Characters are very readable. They have consistent widths across all weights as to not break up words. Commonly used programming symbols such as various kinds of brackets are made easily discernible from each other and various punctuation marks are made bigger than normal. This makes them especially good for programmers who keep staring at code for hours.

I, I, L, l, 1, O, 0, etc.

Iosevka is very clear and legible on all displays and in all sizes.

Narrow character width uses horizontal screen space more efficiently.

This font comes in seven different weights, ranging from thin and extra-light to heavy.

There is full customization of styles and variants in Iosevka.

Iosevka is quite flexible in that it supports Cyrillic and Greek letters.

Iosevka is free and open source.

Includes characters for supporting Powerline/Airline for terminals and terminal editors.

Few fonts have a good ligation feature. Ligature characters (such as æ or the German ß) are supported in Iosevka and look just as you'd expect them to.

IPA is a system containing the sounds of spoken language and includes speech qualities such as intonation.

Many of the common styles are available, including Sans Serif and Slab Serif with normal, bold, italic, and bold italic styles.

Due to it being readable on all types of displays, Iosevka isn't hard on the user's eyes.

The developer is active and responds to user questions and issues.

Iosevka integrates CJK characters well, those being characters of the Chinese, Japanese, Korean, and occasionally Vietnamese languages.

For better reading longer texts.