At DESY the exisitng accelerator complex has been upgraded and partially rebuilt to become the high-brilliance 3rd-generation light source PETRA3. The pre-accelerators have been successfully re-commissioned during the second half-year 2008, while PETRA3 has provided stored beam first time in April 2009. In the context of the PETRA3 project, the control systems of all accelerators involved have been rebuilt. At all levels radical and significant changes have been introduced. Key elements of the chosen architecture and technologies are among others: TINE as core control system software suite, JAVA as the principal programming language for implementing graphical operator applications as well as many device and middle-layer servers (other device servers making use of C, C++, VB, and LabView), integrated Matlab and light-weight dynamic web-based applications, generic device access, CANopen as interface for standard process control, more than 200 LIBERA brilliance beam position internet appliances and integrated high-bandwidth video transmission. The paper reports the experiences gained so far during the commissioning of the new control systems.