There's currently two 2nd layer platforms for smart contracts: Hive Engine and DLUX.
In addition, BlockTrades will be developing a HAF-based smart contract engine, but we don't have a firm timeline yet as we haven't scoped the task yet (we'll start that work after we release HAF itself). But I have my fingers crossed that we can have something before the end of the year. HAF itself should solve most of the challenging issues associated with the development of the smart contract system (easy to program, highly scalable, robust, and a strong security system against rogue contract actions).