UTM is a full-featured virtual machine host for iOS and macOS, built on top of QEMU and Apple's Virtualization.framework. It allows users to run operating systems such as Windows, Linux, and macOS on Apple devices. The application provides a SwiftUI-based interface for creating, configuring, and managing virtual machines, with support for both emulation (QEMU) and native hypervisor (Apple Virtualization) backends. Key features include SPICE-based display and input, USB device passthrough, shared directories, clipboard synchronization, remote access via a custom TLS-secured protocol, and AppleScript automation. The architecture is modular, with separate layers for configuration models (Codable structs), platform-specific UI (iOS/macOS/visionOS), services (VM lifecycle, SPICE I/O, logging), and a remote server/client component. The build system is complex, involving cross-compilation of patched QEMU, SPICE, and dozens of other libraries via shell scripts, and the project supports multiple product variants (standard, SE with threaded interpreter, remote-only).