You can use many graphic programs to alter the brightness or darkness of a photo, but usually only using an auto feature. You can get some quite interesting effects if you use Curves in Photo shop. Once again, I’m using Photo shop 7.

That’s too dark a picture, so:
1. Go to Layer>New adjustment layer>Curves
2. Click group with previous layer
3. Move the curve in the box around until you get the brightness or darkness the way you want it.
4. OK and Save
Result