I am a new user to OpenMX and cannot download it onto the new version of R (see error message below) and I do not know how to download the older version of R (ie. 3.0) onto my Mac.
Any help will be much appreciated,
Warning: unable to access index for repository http://openmx.psyc.virginia.edu/sequential/bin/macosx/contrib/3.1 
package ‘OpenMx’ is available as a source package but not as a binary
package ‘OpenMx’ is not available (for R version 3.1.0)