You can run OpenMx on computers using Windows XP/Vista/7, Mac (Intel or PPC) OS-X 10.5 or later, and varieties of Linux (32 and 64 bit).
In order to install the most recent version of OpenMx, you will need R version 3.0.0 or higher. Version 1.x of the package will work with R version 2.9.x or higher. Unfortunately there is a bug in R version 2.10.0 that prevents the use of our automatic installer.
If you need to download R, it can be found at CRAN.
IMPORTANT: if you are running R 3.1 AND your version of OpenMx is 1.3.2-xxxx or 1.4-xxxx, where xxxx is less than 3475, please re-install OpenMx and re-run any analyses you did with it in R 3.1. Version 3.1 of R introduced a small change in R's interface with compiled code that could potentially cause certain OpenMx scripts to compute numerically incorrect solutions. This problem was fixed as of revision number 3475.
Next, open up an R session and copy the following line into the R command line and press return.
If you don't have a default CRAN repository, you will be prompted to pick one. Just pick a repository near you and press the OK button. If you do have a default CRAN repository, you won't see that panel.
Now you should be ready to take a look at the Tutorial User Guide.
Take a look at third party software that extends the functionality of OpenMx.
If you are interested in building OpenMx from source, take a look at the OpenMx Compilation How-To Guide.