CDEmu is a powerful suite that replicates the "Virtual Drive" behavior of DAEMON Tools most accurately. It consists of a kernel module that simulates a real optical drive.
Often called the "Swiss Army Knife" of image mastering on Linux, AcetoneISO goes beyond just mounting.
What are you trying to mount (.iso, .bin/.cue, .mdf)? Are you trying to run a game or just access data files ?