Some of the “glyphs” (is that the correct term?), like the arrows (->, =>) look nice but some of the other ones (!=, !==) look too similar and would require a double take to be perceived correctly.

It’s an interesting idea and I like the use of the “hidden” features of the True/Open Type System, but I think some of the symbols need a bit more help. Very cool though!

Check out v. 0.5, I’ve made changes to === and !== so they are easily distinguishable from == and !=

I like this! I'd love to see it done for other fonts like Source Code Pro, Consolas, Inconsolata, etc. The only possible problem I see is the == ligature; I think it only invites more mistakes of missing assignment vs comparison.