Linux? yes. Popular distro? not really. Lack of MMU means that all the processes (and shared objects) use the same memory space, so unless you have some way of randomizing where things go (like SELinux), two processes will step on each other's data (MPU will not trigger segfault, as both are allowed to r/w same addr - IIUC). But even when using randomizing, you're playing russian rulette.