Code switching seems to be natural for most multilingual speakers because they can switch from different languages freely depending on what is available in their linguistic repertoire. This collection of studies aims to bring current Malaysian code switching and language alternation research to the attention of a worldwide readership. In so doing we attempt to follow the path taken by our late friend, colleague and mentor, Professor Rodolfo Jacobson. The approach and conceptual framework adopted by the contributors in this volume tends to focus more towards the functional rather than the purely linguistic or grammatical. Research into Malaysian code switching demonstrates the need to seek out ways of merging these approaches, rather than keeping them separate, and several of the chapters in this volume attempt such a merger of approaches and methods.