ACS provides the infrastructure for the software of the Atacama Large Millimeter Array and other projects. Using CORBA middleware, ACS supports the development of component-based software, from high-level user interfaces down to the hardware device level. It hides the complexity of CORBA beneath an API that allows the application developer to focus on domain-specific programming. Although ACS, now at release 8, has been used operationally by the APEX radio telescope and at the ALMA Test Facility, the commissioning of ALMA in Chile brings major challenges: new hardware, remote operation and, most important, upscaling from 2 to 60+ antennas. Work now turns to scalability and improving the tools to simplify remote debugging. To further identify potential problems, the University of Eindhoven is formally analysing ACS. Meanwhile, new developments are underway, both to respond to newly identified needs of ALMA, and those of other projects planning to use ACS. Examples include the refactoring of the interface to the CORBA Notify Service, integration with the Data Distribution Service, generation of state machine code from abstract models and of Python binding classes from XML schema.