Object-oriented programming (OOP) is a mainstream paradigm for engineering design software tool development. An emerging requirement is the introduction of semantics to achieve heterogeneous information sharing, but many challenges exist. Examples include using object methods to manipulate an RDF data, automatically converting data into RDF format, and supporting various programming languages. In addition, limitations to description capabilities for relationships among object-oriented classes exceed those of RDF, thus hindering direct mapping between object-oriented and Semantic Web classes. Our proposed semantic object framework (SOF) combines object-oriented design and Semantic Web features. SOF utilizes embedded comments in source code to describe semantic relationships between classes and attributes. We use a mobile phone design case study to illustrate how the proposed system operates.