Você pode usar o firefox com a extensão Imprimir linha de comando .
firefox -print http://www.example.com/index.html
firefox -print http://www.example.com/index.html -printmode pdf -printfile ../foo.pdf
firefox -print http://www.example.com/index.html -printmode PNG
firefox -print http://www.example.com/index.html -printdelay 10