Yes, sticky menus arrived much later. I put the extra effort to add them here because everyone's so used to them now. Both options work - you can single-click to keep a menu open, or you can hold down the mouse and drag to open a menu which closes when you release the mouse.

There's at least one Mac extension I know of that lets you use sticky menus on earlier versions of Mac OS, like System 6. I figured I'd backport that feature a little further, so to speak...

EDIT: Also, forgot to mention it in this reply, but you double click the titlebar icon to close the window.