Just saw this post and had to respond
I am native to Montreal, born here, raised in B.C. and came back to Montreal when I was 9 and haven't left since. French isn't necessarily a problem here unless you look at it that way. And to ease your mind there are plenty of english schools here; elementary, high school college and university. And it isn't really hard to integrate into society as an anglophone. There is a large anglo community here specifically in the West part of the island. Although french is the official language of Quebec it is pretty bilingual here. Sure, lots of signs, storefronts and businesses are in french but you can make do with english just about anywhere.
On the other hand, as edgarsitow mentioned it would be a good idea to learn the language... not just you, but your children as well. It is after all the official language of Quebec. Just think how your children will benefit being bilingual - it's a great plus for anyone. I didn't have a problem learning that language starting at 9 yrs old. Sure, it was a little hard for me in the beginning but I ended up in a french immersion program and am now fluently multi-lingual.
I work for a major corporation here; sure I use my french from time to time (with clients) but for the most part I use only english (all day, every day) . All of our databases, systems, acceses are in english and 90% of my colleagues are english speaking as well. Not a problem! And I'm sure there are several other companies just like this in the city. As a software engineer I don't think you'll have a problem.