It used to be typical of most computer programs to have
Options etc. across the top of the application window. I have noticed that, starting with browsers, many programs have gotten rid of this and now have one big button in the top left. For example, Firefox has a big orange button and opera has a red one.
Is there a reason why this change was made? What effects does it have on productivity and usability? Aside from web browsers, the only other program I've noticed to follow suite is Microsoft Office 2010. Has anyone seen others? By the way, is this there a name for this type of menu, since it's not displayed on a user event it's not a context menu?
To clarify here is Internet Explorer 10 which has the way I'm used to seeing
Here is Firefox with an arrow pointing to what I'm talking about