Why do they? Tons of people are working on it, and no doubt someone will do it. There's plenty of push without the additional payoff of exclusivity. I'm a professional programmer, I should add. The problem is, almost everything in software IS obvious about 1 year later. JPEG is totally "duh" for example, take the furrier transform, drop a few bits off all frequencies, convert back. Doing this drops the pieces of the image you are least likely to notice, it's some trivial mathematics, and anyone with rudimentary knowledge in the field could easily come up with it. I would be very hard pressed to find an algorithm that someone wouldn't likely come up with when working on the problem domain. 3DES, blowfish, SHA1, and a few of those algorithms, simply because they are fundamentally arbitrary. Note, I was specific, RSA (which was patented) is pretty obvious for example. Imagine if someone had patented UnionFind, BinarySearch, MedianFind, Quicksort, MergeSort, B-trees, Red-Black trees, scape-goat Trees, heaps, treeps, etc. ALL of these algorithms are fairly obvious once you start digging into that problem domain. The people who came up with them were brilliant, no question, but when you try and solve a certain type of problem you write a certain type of algorithm. I accidentally invented UnionFind once before I knew it existed. The only purpose of patents is to encourage people to invent things. I actually suspect the entire concept is antiquated now, but I don't know other domains well enough to be sure. In software it simply isn't necessary, people invent things daily, and any real product is sufficiently covered by copyright. Patenting software is like patenting a literary method or trope. "You can't write a novel where an airplane gets hit by lightning, that's MY idea!" or "You just used alliteration with a's, I patented that for the purpose of being hilarious, sorry"... what?

... That just makes my head hurt. Is that a troll? WTF. 1) Linux is not an OS, it's a kernel (technically, this is pedantic I admit) 2) UNIX is an OS, which predated Linux. Linux is not UNIX in any way. It is not "UNIX based" 3) Linux is a Unix. That means it conforms to the Unix spec (sortof). It has no "Unix" source or anything (ever taken an OOP class? Is-a vs. has-a relationship?). 4) OS X is a Unix, it is not a Linux. OS X runs on Mach Darwin, which is not a Linux. It is actually BSD - twice over, BSD running under BSD. where Mach2 is BSD derivative, as is Darwin. Additionally in response to a later comment OS X does not *actually* run a microkernel, as these are collocated, both running in ring 0. This is a common confusion due to a misunderstanding that Mach2 is not a microkernel, but Mach3 is. 5) Ever heard of RedHat or Suse? Both are "major corporations", and these days Suse is damned near owned by Microsoft. Holy god, learn something or shut up.