Ranked in these QuestionsQuestion Ranking
Pro Italics look good
The handwritten-style italics of Fantasque Sans Mono are quite attractive.
As a "Mono" font, Fantasque is uniform in size and overalls. However, if you look further into all characters, you'll find that there's almost no pattern between them - except for the huge amount of curves. That said, this font is a very strong contender in terms of readability, especially in a world that seeks pattern (often too much).
Pro Open source
Fantasque Sans Mono is open source, meaning it can be freely used, changed, and shared by anyone.
Pro No useless experiments with special characters
Pro Glyphs support
This is good for those who wish to use different designs of a certain character.
Pro Cyrillic alphabet support
This is useful for those who wish to use letters from certain Eastern European or Asian alphabets.
Pro Own personality
It looks distinct, playful. But don't cross the line when it becomes unusable.
Pro Support for various platforms
There's support for OS X, Linux, and Windows (otf, ttf) in Fantasque Sans Mono.
Pro Lowercase "k" looks nice
Pro Webfonts included (eot, svg, woff)
Webfonts, such as eot, svg, and woff, are included in Fantasque Sans Mono.