How to Make an Inferno
Learn how to create your own inferno from scratch from the conform and safety of your chair!
Open the GIMP and create a new image. I made mine 800px by 600px.
Now create a radial gradient in the center of your canvas, orange (#ff9600) in the center and fading to black. Now duplicate your layer and set the top layer's mode to dodge:
Filter > Render > Clouds > Fog.
Duplicate the fog layer. Set both fog layers' modes to Overlay.
Create a new layer. Filters > Render > Clouds > Plasma. Filters > Blur > Gaussian Blur (25px). Colors > Desaturate. Duplicate the layer. Set both layers' modes to Overlay:
Image > Flatten Image.
Filters > Blur > Motion Blur:
And you're done!