Why is Linux the only OS in version identifier list that has a lowercase name?

[Zekereth via Digitalmars-d-learn]

On Monday, 11 April 2016 at 01:15:27 UTC, Ali Çehreli wrote:
> As a workaround, you can set version to Linux yourself:
>
> version (linux) {
>     version = Linux;
> }
>
> void main() {
>     version (Linux) {
>         import std.stdio;
>         writeln("Linux worked!");
>     }
> }

That's interesting that will help. Thanks for that!