No mention on the website that I can see, but my guess be they won't explicitly require French language exams for the visa, but not speaking French in France is

No mention on the website that I can see, but my guess be they won't explicitly require French language exams for the visa, but not speaking French in France is going to be difficult, particularly in the North (including Paris). It may well be that the right firm, in the right part of France (the South is normally a little friendlier), you're going to be fine. In Paris though? It seems like it is almost a national sport to be a little rude to non-native speakers, and a lot more rude to people who just try and get by in English. But if you're planning to move to France, to start a French start-up business, and employ French employees, it is probably a good idea to learn some French. As an English speaker, the michelthomas.com courses point out that you already know a lot more French than you think. :-)