Today, Wizards of the Coast released the Original Edition - aka White Box D&D - in PDF.
I didn't get it, because I have all of the books already.
But it's on my list for their next sale.
It seems like, at least up to 4th edition, you can get the core rulebooks for almost all of the earlier D&D editions.
So what have we got?
B/X & the Cyclopedia
1st Edition AD&D
2nd Edition AD&D
3rd Edition D&D
4th Edition D&D
5th Edition D&D (no rule books yet, that I can see)
Nice. I'm glad people who want these books, and who don't have them, can finally get to own them all legally and buy them on demand.