So you want a powerful but lightweight and best of all free image editing tool?
Look no further.
Every web developer have to do some image editing at some point even if it just something simple like resizing or rotate the image, of course this tool can do much more.
its just amazing. Its not to meant to be a photoshop but it does help you a lot when you need.
Cank goes Technical 
Este ou o Gimp? Qual é o melhor afinal?
nao te sei dizer. antes tinha o gimp instalado, e ate gosto do gajo mas akilo demorava bue a iniciar tipo kuase um minuto ou mais. Na minha maquina do trabalho puseram este paint.net e agora que formatei o pc, pus este tambem. vamos ver o que da.