I am a strong proponent of Nim but this is probably the worst idea I have ever encountered in language development. Honestly!
Partial case sensitivity and the special underscore case are features I can live with. Unfortunately this has actually become a stumbling block for a wider adoption of Nim.
All strange special features should be optional, not default.
What makes you think this is default? It most certainly is not and will be removed completely in the future.
Edit: here is a source: http://nim-lang.org/docs/manual.html#syntax-strong-spaces ("... if the experimental parser directive #?strongSpaces is used..."). The last time this was discussed I said that it would be removed completely, and I still believe it will be. It's simply not a priority for us right now.
Some of those features are default in Nim, some (strongspaces) are not. I say that all such weird features should be optional in general so that newcomers don't get scared off.
Also case and underscore should work like in C per default since Nim interoperates with C seamlessly anyway. Case insensitivity and ignoring underscore are ok if optional.
