While the original C code [7] released by Google does an impressive job, Gensims' implementation is a case where an open source implementation is more efficient than the original.
The Gensim implementation was coded up back in 2013 around the time the original algorithm was released – the blog post by Radim Řehůřek [8] chronicles some of the thoughts and problems encountered in implementing the same for Gensim, and is worth reading if you would like to know the process of coding word2vec in Python. The interactive web tutorial [9] involving Word2Vec is quite fun and illustrates some of the examples of Word2Vec we previously talked about. It is worth looking at if you're interested in running Gensim Word2Vec code ...