Final answer:
The abbreviation is IFC (Industry Foundation Classes), which is integral to the BIM process for sharing and exchanging data amongst various stakeholders in the building industry.
Step-by-step explanation:
The abbreviation for the open specification for an object-oriented file format for BIM modeling, developed and maintained by buildingSMART International, is IFC, which stands for Industry Foundation Classes. This file format facilitates interoperability in the building industry by providing a common language for various software applications to share and exchange building information models. IFC is widely adopted as it supports the open and collaborative work processes of the BIM methodology, allowing different stakeholders to contribute to a BIM project effectively.