I'm not sure that you can compare them as purchasable products, though. they are embedded products.
the only one to sell tesla software is tesla.
otoh, I expect many vendors to latch on to 3rd party *working* sw and M.E. seems like one of the leaders of the pack.
one huge diff: tesla never intended their software to be portable to other architectures/cars. so, really, it would be too much effort for any car company to buy and integrate tesla's sw.
imagine having to DEAL with tesla as a SUPPLIER! I shudder at the thought!
no, no one would want to even try integrating tesla's software. and they are too far along to go with something more standard and portable (as much as I dislike much of its aspects, autosar IS the only real standard out there and if you want to mix/max more advanced ecu's you'll need to at least speak autosar API to them.
when you go it alone, you have to patch your own stacks, write all your own drivers and new code and tbh, tesla has run into a wall where they just cannot manage this much tech and keep it moving forward at their 'old rate'. the legacy code (we call it 'built up technical dept') will catch up with them, as I bet it already has. its also why you hear about 'rewrites', periodically.