The program could become your main downloads manager, bringing all your standard internet downloads, those from special services, and even special formats such as YouTube videos, into one place.
One of the features that has made JDownloader a success is its capacity of easily downloading files from services such as Mega and Rapidshare, automatically and sequentially processing all files you add to the queue, whether you are a premium user or not.
It is free and open-source, and it will help you download files from several different hosting services on the internet, optimizing downloads and letting you manage multiple active transfers from its own interface. JDownloader is a Java based aplication for Mac.