According to this blog entry :
IOTA does not “natively” support smart contracts. The IOTA Foundation has publicly stated, that smart contracts will not be a feature of the IOTA core but provided as a layer on top. And it’s also public knowledge, that IOTA Foundation is actively working on this additional smart contracts layer which will likely need until the end of 2018 to become GA.
So, now it's the time to say that "Qubic" is programming language to develop the IOTA Smart Contract? And what is its difference with "Abra"? And is there any handbook for how to use it?