conch (Contract Checker) is a tool that we have implemented for monitoring and enforcing executable contracts at run time.
An executable contract (also called a smart contract) is (at least under my personal definition) a conventional contract that can be converted into executable code, executed and enforced programmatically at run-time.
The main feature of a smart contract is that its executable and capable of monitoring and enforcing contractual commitments (rights, obligations and prohibitions) at run--time.
A smart contract can be implemented using a centralised or a distributed approach. The distributed approach involves the achievement of consensus between several remote parties, consequently, the implementation of distributed smart contracts is significantly simplified by the support of middleware services offered by blockchain technology.
The current implementation of conch follows a centralised approach and therefore, does not rely on blockchain.