Blockchain technology has created a new software development context, with its own peculiarities, mainly due to the guarantees that the technology must satisfy, that is, immutability, distributability, and decentralization of data. Its rapid evolution over the last decade implied a lack of adequate verification tools, exposing developers and users to critical vulnerabilities and bugs. This paper clarifies the extent of block chain-oriented software (BoS), that goes well beyond smart contracts. Moreover, it provides an overview of the challenges related to software verification in the blockchain context, encompassing smart contracts, blockchain layers, cross-chain applications, and, more generally, BoS. This study aims to highlight the shortcomings of the state-of-art and of the state-of-practice of software verification in that context and identify, at the same time, new research directions.