MATLAB R2013b is live for download on MathWorks.com. Here is a list of Simulink-related features I find particularly interesting:

Simulink

• MATLAB System block: My favorite new feature in R2013b. This block is the ultimate user-defined function block, combining the best of MATLAB Function Blocks and S-Functions. This has been requested by many users (for example here) and is now a reality.
• LCC compiler is now included with MATLAB on Windows 64-bit machines: No need to install the Microsoft SDK anymore!
• Comment through blocks: In R2012b, we allowed commenting out blocks. In R2013b, we added the possibility to comment through blocks. If the block has the same number of inputs and outputs, a commented through block behaves like a direct line between the input and output.
• Improved Mask Editor: The Parameters & Dialog Pane gives you more control over the layout of parameters, and the possibility to include links and images. Your masked subsystems will look better than ever!
• Variant Manager: A new interface to help >managing multiple variant configurations.
• Hardware support: The Arduino target is now hardware available on Mac OS X. Simulink R2013b supports the Arduino Ethernet Shield and the Arduino Nano 3.0

Physical Modeling

• New Thermal Liquid domain in Simscape Foundation: You will now be able to simulate heat generation and dissipation in hydraulic networks.
• SimPowerSystems Third Generation: A new library to simulate electrical power systems that is fully compatible with the Simscape Foundation Library.
• Motion Actuation in SimMechanics Second Generation: Now you can apply forces and torques at joints! See the demo titled Computing Actuator Torques Using Inverse Dynamics for a good example.

Now it's your turn

Give a look at the release notes for the family of Simulink-related products and let us know what is your favorite enhancement by leaving a comment here.