Just as a curiosity, complementing what others have already written... I read part of Mikolov's thesis and code in the past (when I was still studying at the university, so I might have got everything wrong (I still don't get half of it :D)). First I found it quite shocking that the code was so bad. The training code was pretty confusing to me, and I found the lack of useful comments discouraging. The test code (which loaded stored embeddings from a file and allowed some basic operations) was even much, much worse. Like, declaring three variables (a, b, c) and reusing them for different things in the main functions without explaining anything, and doing linear searches through the whole embeddings to find a word vector... very ugly and scary things.

So, I had a very bad impression of the code. But then, I checked the thesis, and I found it awesome. The amount of tests and implementations the guy made, and how he showed in practice how better results could be achieved in a good number of different setups... I found it really impressive. But such great work paired with such bad code! I was just a CS student, so I found it shocking. Nowadays I realize he was simply focused on a different thing, and the results he obtained were indeed outstanding and talk for themselves.

It's easy to look back and criticise the code, but when you look at the work he did in perspective... it's completely unfair to ask more from him (admittedly, they had time to address some of the issues later, but they probably had better things to do too).