Anyone who still uses Limewire really needs to go here
. Frostwire is like Limewire Pro for free. You get the "turbo-charged downloads" [you connect to more ultrapeers, therefore potentially increasing download speed and search results], and all the other "features" that Limewire Pro has for free.
As for the original thread topic, Limewire itself is legal, however what 99.9% of its users download is not.