DOSBox is a DOS-emulator that uses SDL-library to run old DOS-based applications and games on modern computers by emulating an IBM PC, as well as the necessary hardware around it. It also allows you to make use of virtual hard drives, mount ISOs to virtual CD-ROM drives, cast and capture your emulated display, and many other quality of life features.
As a fork of DOSBox, it retains compatibility with the wide base of DOS games and DOS gaming DOSBox was designed for. That said, it goes further, with a focus on accurate emulation of the hardware and many more ways to tweak and configure the DOS virtual machine. They believe that a better way to emulate the legacy PC platform is to give the user all the options they need to emulate everything from original IBM PC hardware with 64KB of RAM all the way up to late 90's hardware, whatever it takes to get that game or software package to run. Their goal is to eventually make DOSBox-X a complete emulation package that covers all pre-2000 DOS and Windows 9x based hardware scenarios, including peripherals, motherboards, CPUs, and all manner of hardware that was made for PC hardware of that time.
DS4Windows is a portable program that allows you to use a PlayStation DualShock 4 on your PC by emulating a Xbox 360 controller. This project is actually a fork of the work of Jays2Kings, which can be found on the old project website at ds4windows
JoyToKey enables PC game controllers to emulate the keyboard and mouse input, so that windows applications and web games can be controlled with your joysticks. Whenever buttons and sticks are pressed on the controllers, JoyToKey converts them into keyboard strokes and/or mouse movements so that the target application will work as if a real keyboard and a mouse were used.
Launchbox is a front-end wrapper for emulators. Not only does it automatically download box art for games, it also grabs fanart, screenshots, logos and more to create an immersive experience via BigBox.
It also supports arranging and filtering by genre, platform, ESRB rating, developer, publisher, genre, etc. It also includes automated import processes for your MS-DOS games, ROM files, and Steam in order to help get you up and running as quickly as possible. Game box-art and metadata can also be automatically downloaded from their Games Database or community-based online databases.