There are a lot of fan-made clip-laden vids to honor the BBC TV series DOCTOR WHO's 50th anniversary this year, and this is (I think) one of them. Expertly edited, with every Doctor you've ever seen -- it popped onto the Web a week ago. Den of Geek picked it up, and now Life, Doctor Who and Combom.
It's not about the big, new special that stars the previous two Doctors (plus John Hurt as another Doctor) that will air in two months. But it IS a lot of fun and encapsulates a lot of why there are "77 million fans worldwide."