With emerging areas such as Web services, pervasive computing, wireless sensor networks and so on, self-adaptive software is becoming more and more important and topical. As a new emerging discipline, self-adaptive software has strong background in control theory. This work analyses the similarity between software self-adaptation technologies and control theory, and shows that self-adaptive software could be studied from software cybernetic perspective. Based on this standpoint, we also present three software adaptive models derived from open-loop control, feedback control and adaptive control. The application server based implementations of these three models are introduced.