Made of a number, a Kolkata train,
My purposes now seem so plain.
And though I seem to scream and shout,
It's data and numbers I care about.
You used to love me, it's tried and true.
Not much to see now, nor much to do.
And though my fans became such hacks,
I sent some to the moon and back.
Try to assemble the language used to find the pattern and solve the riddle!
Yes, the title is a hint.
You can use Google translate for the first line if you'd like. I did.