Softaculous is an Instant/Auto Installer. Softaculous helps users to install free/opensource softwares in minutes. A user can install a software, available in Softaculous, without having to download/upload any files, change any files.
Additionally a user to choose the software they think is the best, after showing them ratings voted by users who have already tested and used the softwares.
In short, Softaculous just helps you to install softwares really FAST.