This paper proposes a framework for the specification of open environment properties. This framework enables convenient and formal specification of properties of asynchronous environments, including temporal properties which cannot be handled in the existing work. This framework also supports implementation of effective schemes for monitoring environment properties based on distributed predicate detection. A middleware infrastructure is designed and implemented, which supports efficient monitoring of environment properties for building high-confidence systems in open environments. This paper also evaluates design of the proposed infrastructure with a case study.