Gmagick is a php extension to create, modify and obtain meta information of images using the GraphicsMagick API.
Imagick is a native php extension to create and modify images using the ImageMagick library
"Gmagick is newer version of imagick with more set of features it is less resource intensive and fast but the problem is there is very few discussion about this wonderful tool on web i recently came across this on"
from question "How to install gmagick extension of php on windows vista"
"Update graphicsmagick is faster than imagick doesn t means gmagick is better than imagick"
from question "Fastest way to read pixels from an image"
"Imagick is more resource hungry than gmagick but when i tried to use gmagick it is not working properly"
from question "Image processing extension for php"