openPSTD is an open source initiative to provide an intuitive visual interface for the Pseudo-Spectral Time-Domain method to simulate the propagation of sound. Documentation on openPSTD can be found here. Version 1.0 and 1.1 of openPSTD are written in Python and these are released as Blender plugins; for instruction on installation, see Installation.
openPSTD is licensed under the GPL open source license, because we think it is important for our users to have the freedom to use and adapt openPSTD freely in their academic and commercial projects. Furthermore, we believe in a collaboratively development model and we welcome contributions from other experts. Note that conditions apply if you wish to redistribute a modified version of openPSTD.
Download the most recent release of openPSTD from this link and install the add-on by clicking on the 'Install from File...' button in the User Preferences > Addons window in Blender. Blender 2.70 or newer is required to run the add-on.
Some additional work is required to enable GPU acceleration. For a detailed explanation, refer to the relevant page on the wiki here.