Requirements: The standard VMD builds require MacOS X 10.4.7 or later.

Tk, and TkCon bugs: Users running MacOS X on Intel based Macs have reported several bugs that are attributed to the MacOS X version of Tk. The most serious of these is a situation where TkCon becomes unresponsive and stops responding to keystrokes. When this occurs, proper function can usually be restored by selecting another application window (not VMD), invoking the MacOS "expose" feature (press F9, or Fn-F9 on the keyboard), and selecting the TkCon window again. This will restore the keyboard focus to the TkCon window. Future versions of VMD will use a newer Tcl/Tk version that we hope will fix this problem.

In order to use features such as the 'vmdmovie' plugin, you would be well advised to install the "Fink" package manager, so that you can easily add related software such as the NetPBM image toolkit with simple commands such as "fink install netpbm".

MSMS: Until native versions of MSMS are available for MacOS X on Intel, it is necessary to set the VMDMSMSUSEFILE environment variable to work around incompatible endianness when running the PowerPC version of MSMS through the MacOS X Rosetta emulator.


Stereoscopic Display: VMD supports stereoscopic display on appropriately equipped Macs, however the VMDPREFERSTEREO environment variable must be set to inform VMD that you want it to acquire a stereo-capable display window. This is done for performance reasons, as VMD would otherwise have a lower display rate, even when not using stereo, as a result of some limitations with the current Apple stereo display driver implementation. This variable is set in the .profile with the commands:


Enabling advanced OpenGL rendering features: At the time of the release of VMD 1.8.6, the shipping versions of MacOS X contained a number of OpenGL bugs which detracted from the stability of VMD, so these unsafe features have been disabled by default on the PowerPC builds of VMD where the stability problems occured. These features can be re-enabled with the following additions to your .profile:

# enable all OpenGL extensions by default

# disable the multi draw arrays extension that is still unsafe

OpenGL Programmable Shading: At the time of release of VMD 1.8.6, the shipping versions of MacOS X contained bugs in the implementation of OpenGL programmable shading. The symptoms are that VMD shaders compile with no errors at program startup, but if you change the Display->Rendermode setting to GLSL, all shaded geometry will disappear and/or be drawn solid black. A workaround is available which disables the use of depth-cueing, user-defined clipping planes, and the color-by-volume feature of VMD. If you're interested in getting a copy of the GLSL shaders that run with the current MacOS X drivers, send email to We hope that Apple will soon fix these bugs and that the standard VMD GLSL shaders will work with no modifications in the near future. Users of the PowerPC Mac versions of VMD will still need to enable extensions as described in the note above.