MATLAB can call functions built into a DLL. It can call other programs by using system() and passing in command line options. With the Instrument Control Toolbox it can communicate with other programs through TCP/IP. On MS Windows systems, it can call ActiveX / COM controls.
MATLAB can be called by other programs using the MATLAB engine API. On MS Windows sytems it can also be invoked as an ActiveX server. With the Instrument Control Toolbox, it can act as a TCP or UDP server.
With the MATLAB Compiler SDK toolbox, MATLAB can be invoked from Java or .NET .
The range of software that MATLAB has been integrated with is quite large; see for example https://www.mathworks.com/products/connections.html
