You can read the announcement here: https://mozillalabs.com/blog/2011/02/prism-is-now-chromeless/ https://mozillalabs.com/blog/2011/02/prism-is-now-chromeless..

You can read the announcement here: https://mozillalabs.com/blog/2011/02/prism-is-now-chromeless/ https://mozillalabs.com/blog/2011/02/prism-is-now-chromeless... Basically: Both can solve the same problem, but Chromeless is more powerful.