One of the challenges in managing a platform built on services and apps, running on different and hardware and software environments, is the integrity of the cryptographic data: current state-of-the-art cryptography is not fully deterministic and can't ensure consistent results in a multiplatform setup.
A virtual machine is an elegant solution to this problem, as it ensures a consistent and deterministic execution of cryptographic functions. Zenroom runs independently from its underlying OS, cause it uses its own built-in pseudo-random number generation function and allocates its memory allocation directly: this combination ensures that complex cryptographical flows can run a variety of platforms.