Ranked in these QuestionsQuestion Ranking
Pro Has a heavier appearance than Fira Code or Monoid.
Pro Great for Haskell
Pro Has many variants such as Italic, Bold Italic, Light, Semibold, etc., etc.
Pro Completely free and open source
Freely available via GitHub, therefore can be modified and improved by anyone
Con No support for many editors, including emacs
Unfortunately, not supporting emacs is the number one reason I don't use this font all the time.
Con Lacks !=
Some coding fonts with ligatures, like Fira Code, turn != into ≠, but Hasklig does not. The reason for this is that Hasklig was designed for Haskell code, and so turns /= into ≠ instead.
Con Very cute but not WYSIWYG.
You want to see exactly what you've typed, not have your brain have to do a little dance every time you see one of these artifacts.