Originally Posted by
bluehills3149
Aside from Microsoft, there's also Sensah, whose action mimics double-tap (and has been available in 12spd for some time) or LTWOO where the shifting resembles Campagnolo with a thumb button for down shifts. As for licensing, the patents mostly expired years ago so they're free game to copy.
I am far from even literate when it comes to copyright law. I have heard '20 years' all my life so thats what I assume. Shimano started internal cables 13ish years ago, so then their patents limit others from using the same design for another 7ish years, right? And SRAM introduced their drop bar tech 15ish years ago, so its another 5ish years for them.
^that may all be totally wrong, I fully admit.