Here are just a few to get you started. More to come…
- A-Frame : free, web-based, simple markup language.
- ARToolkit : free toolkit for AR programmers (with Unity plugin).
- inVR : create a 3D model with Blender, SketchUp, 3DS Max, etc. then upload to inVR to share it as a web-based VR experience.
- OSVR : an open source VR and AR toolkit supporting many input and display devices (plus their own open source head-mounted display).
- Unity : very popular game engine, but much more than games. There is a free version.
- Unreal Engine : another popular game engine. Free for non-commercial use.
- Vizor : easy, web-based 3D editor and publishing.
- Vuforia : popular toolkit for AR (with Unity plugin)
For hardware manufacturers’ drivers, development kits (SDKs), etc, there are links on the hardware page.