Difference between __gshared and shared.

[Olivier Pisano via Digitalmars-d]

On Wednesday, 8 July 2015 at 09:20:58 UTC, wobbles wrote:
> After reading the recent "Lessons Learned" article [1], and 
> reading a few comments on the thread, there was a mention of 
> using __gshared over shared.
>
> What exactly is the difference here?
> Are they 2 keywords to do the same thing, or are there specific 
> use cases to both?
> Is there plans to 'converge' them at some point?
>
> [1] 
> https://www.reddit.com/r/programming/comments/3cg1r0/lessons_learned_writing_a_filesystem_in_d/

You can read it there : 
http://dlang.org/migrate-to-shared.html#gshared

Basically, __gshared is for interfacing with C (where everything 
is shared by default) without marking data as shared.