Azure Sphere OS vs OpenWrt

Azure Sphere OS is a custom Linux-based operating system for supported devices, included in the Azure Sphere solution for the MT3620AN. That solution bundles a certified MCU, an Azure Sphere OS license and access to Azure Sphere Security Service; the components are sold together. Ongoing OS updates are included. Listed capabilities include over-the-air updates, fleet provisioning and certificate management. Supported protocols and interfaces are TCP/IP, Wi-Fi, UART, SPI, I2C and GPIO. Deployment is described as hybrid, and the listed platform is web. Azure Sphere is paid and has no free plan. No price is listed for the Azure Sphere solution. The offering combines hardware, operating system licensing and security service access in one package for supported devices, with provisioning and update capabilities for device fleets.

OpenWrt is a Linux operating system for embedded devices, commonly wireless routers. Its writable filesystem and optional package management let users customize devices by adding packages; the project lists more than 27,000 packages and services. Configuration is available through an SSH command-line interface or a web interface, and the Table of Hardware helps check device support before installation. Hardware capacity is a key consideration: OpenWrt identifies 8 MB flash and 64 MB RAM as bare minimums, while warning against devices at those limits for current, secure use. The downloads page lists OpenWrt 25.12.5 as the current stable release and describes development snapshots as generally untested. The older 24.10 release is slated to receive limited security and bug fixes for some time. OpenWrt is free software, with no subscription or licensing fees. The project says users should know GNU/Linux and basic networking concepts before installing it; voluntary support from developers and users is not guaranteed.