I don&#x27;t think there&#x27;s a reason why it <i>couldn&#x27;t</i> happen at least in parts – it sounds like that&#x27;s Mozilla&#x27;s plan for migrating parts of Gecko – but I suspect you&#x27;d hit an 80&#x2F;20 rule pretty hard where many programs could use your alternate libc but a fair amount of code would have different results due to arcane details for things like threading, signal handling, etc. and it would be quite time-consuming to hit complete compatibility.