86Box vs Redream

86Box is a free emulator for x86-based IBM PC systems and compatibles, covering machines from 1981 through PCI-bus systems. It emulates processors from the 8086 through the Pentium with an emphasis on accuracy and supports configurable machines such as the IBM PC 5150 and IBM PS/2 line. Users can select video adapters, sound cards, network adapters, hard-disk controllers, and SCSI adapters. Supported guest systems include MS-DOS, older Windows releases, OS/2, many Linux distributions, BeOS, and NEXTSTEP. MIDI output can use Windows MIDI support, FluidSynth, or emulated Roland synthesizers. 86Box runs on Windows, Linux, and macOS and is released under the GNU General Public License version 2 or later. The project offers stable and experimental builds; experimental versions may be less stable or slower. Most emulation logic runs in one thread, so results depend on host and guest configuration. A BIOS is required. The project recommends manager applications for multiple virtual machines, while its built-in manager is still a preview.

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.