What is the difference between gVisor and Firecracker?

gVisor is an application kernel, often called a user-space kernel, that intercepts system calls from a containerized application and handles them within a sandboxed environment, isolating the application from the host kernel. This provides a strong security boundary without the overhead of a full virtual machine. In contrast, Firecracker is a Virtual Machine Monitor (VMM) that utilizes the Linux Kernel-based Virtual Machine (KVM) to create and manage minimalist micro-VMs. This approach provides hardware-virtualized isolation, which is ideal for secure, multi-tenant workloads like those in function-as-a-service (FaaS) platforms.

B. This option incorrectly swaps the definitions of gVisor and Firecracker. Firecracker is the VMM, and gVisor is the user-space kernel.
C. They are distinct isolation technologies, not interchangeable container runtimes. Their performance, compatibility, and security trade-offs are fundamentally different.
D. They are separate, competing technologies developed by different organizations (Google for gVisor, Amazon/AWS for Firecracker) with different underlying architectures.

1. gVisor Official Documentation: "gVisor is an application kernel

written in Go

that implements a substantial portion of the Linux system call interface. It provides an isolation boundary between the application and the host kernel."

Source: gVisor Project Documentation

"Overview

" gvisor.dev/docs/.

2. Firecracker Official Documentation: "Firecracker is an open source virtualization technology that is purpose-built for creating and managing secure

multi-tenant container and function-based services... Firecracker uses the Linux Kernel-based Virtual Machine (KVM) to run workloads in lightweight virtual machines

called microVMs."

Source: Firecracker Project Documentation

"What is Firecracker?"

firecracker-microvm.github.io/.

3. Peer-Reviewed Academic Publication: "Firecracker is a virtual machine monitor (VMM) that is purpose-built for running serverless functions and containers safely and efficiently... Unlike general-purpose VMMs

Firecracker is minimalistic."

Source: Agache

A.

et al. (2020). Firecracker: Lightweight Virtualization for Serverless Applications. 17th USENIX Symposium on Networked Systems Design and Implementation (NSDI '20). Section 1: Introduction. (Available via USENIX Association).