Camera Space Particles.

Distributes particles only around the camera, so, no need to create big particle systems for global effects like snow, rain, etc.

No need to simulate or bake.

Works with Blender 3.3 or newer.

Limitations:

- Particles are not simulated, they are fully procedural. So, animating parameters in "Physics" section can give unwanted results.

- It works per camera. If you have multiple cameras in your scene, you may need to attach separate particles to every camera and hide/unhide the particles when switching between cameras.

Update:

  v1.1:

    - Added panoramic camera support for Cycles. You may need to increase particle count for this.