[husam212]

It is a completely different approach, instead of sandboxing potentially malicious software, prevent it from getting into your machine, this approach works for open-source only.

Most popular distors provide similar stuff to PPA, the AUR in Arch for example.

[viraptor]

This is the perfect and not possible territory. Even with full access to the source, you can't be sure if it's malicious, or if it can be made malicious at runtime.