&gt; When has something (in software) been invented by building on some text in a patent filing?<p>Hah!  That&#x27;s a great way to put it.  Patents are supposed to be an exchange of (1) opening the idea to the public for (2) protection.  Software patents, to my knowledge, do not do (1).<p>Arguably, other industries suffer the same trouble.  Patent filers these days go to great lengths to disguise their meaning so that they are ambiguous enough to cover many things, and presumably, difficult to actually understand and borrow ideas.