> In my email to mom, I'll write "Please open MyFile.txt" and when mom sees theat there is a myFile.txt and MyFile.txt in the directory, she won't have trouble

> In my email to mom, I'll write "Please open MyFile.txt" and when mom sees theat there is a myFile.txt and MyFile.txt in the directory, she won't have trouble figuring out which one I meant." But if she (or any normal user) only sees 'myfile.txt' or "myFile.txt" or "Myfile.txt", she wouldn't respond with "that file doesn't exist." Instead, she'd be more likely to assume you made a mistake in your specification. Read through the comments on the LWN article: case insensitivity is a practical problem because user-space implementations (such as samba) must perform an O(N) check across all files in a directory before confirming that a file doesn't exist. At the same time, existing programs that assume case-insensitivity (coming from the Mac and Windows worlds, mostly) are often none too consistent about creating 'foo.txt' but opening it (potentially from another program) as 'FOO.TXT'.