QEMU vs Redream

QEMU is a free, open-source machine emulator and virtualizer. System emulation models an entire machine, including its CPU, memory and devices, so it can run a guest operating system. User-mode emulation runs processes built for one CPU architecture on another. The package also includes qemu-img, a command-line utility for creating, converting and modifying disk images. QEMU can work with KVM, Xen and Hypervisor.Framework so guests can run directly on the host CPU. Supported build platforms include Linux, macOS, FreeBSD, NetBSD, OpenBSD and Windows. Windows support is limited to 64-bit, while macOS requires the newest version currently available; support for the prior version is eventually dropped. For complex networking and storage configurations, the project recommends management tools such as virt-manager. Its security guidance distinguishes virtualization with an accelerator and listed machine type from TCG non-virtualization use, which does not provide guest-isolation or security guarantees. QEMU is released under GNU GPL version 2, with some components under specific licenses.

Redream is a Dreamcast emulator for Android, Linux, macOS, and Windows. It lets players run Dreamcast games, with the homepage listing rendering at 1080p or 4K and play without controller setup or adding BIOS or flash files. The homepage says more than 95% of the Dreamcast library can be played from start to finish; the download page gives a figure above 96% and says that share can be played at no cost. Listed features include widescreen codes, automatic cover art, save states, and cheat support. The package is under 4 megabytes, and the homepage says it can produce a smooth 60 Hz on decade-old desktops and mobile phones. Redream is free to use on supported platforms. Premium is a one-time purchase that works across those platforms, with pay-what-you-want amounts of $6, $8, $10, or $20. It adds high-definition rendering, multiple save-state slots per game, and a custom Discord server role.