Nim has solved this in a very practical way, which works great - case insensitive except 1st letter, and underscore insensitive. So hello_world and helloWorld and hello___wOrlD are the same identifier, though HelloWorld and hello_world are not.

Many people complain that this is horrible, but not people who have actually tried it. It works very well, lets you bridge over differences in C++ library conventions, Unix C conventions and Microsoft conventions in a project that interfaces all of them, without getting users upset. (There’s more to it - consistency for some identifier can be enforced, there’s a smart source reformatted, and more)