Here is an update of my previous post on this topic. IBM ILOG CPLEX Optimization Studio (CPLEX) is free for for academics thanks to the IBM Academic Initiative. If you are not a faculty member, you may be interested by the free trials available on our developerWorks site.
IBM Academic Initiative (AI) is a global program that faculty members, research professionals at accredited institutions, and qualifying members of standards organizations can join. Members can get full versions of a large selection of IBM software, including CPLEX at no charge. More information about IBM ILOG Optimization products in the IBM Academic Initiative can be found on this page http://www-304.ibm.com/ibm/university/academic/pub/page/ban_prescriptive_analytics.
Steps to use the latest CPLEX release via AI are the following. Step 1 can be skipped if you are already registered. Registration needs to be renewed every year.
Register, or renew your membership if it is older than a year, on this page http://www-03.ibm.com/ibm/university/academic/pub/page/mem_join. Given it requires some manual valdation this step may take time. You should receive a confirmation email when it is completed.
Once registered, read instruction on how to download CPLEX on this page: http://www-03.ibm.com/ibm/university/academic/pub/jsps/assetredirector.jsp?asset_id=1070 . It will lead you to a the search on the AI software catalog, see picture below. I recommend you use download director (default) and not http as it is more robust. Select the latest CPLEX version (12.6 in the picture below), then select the image that fits the operating system of your target machine.
Once downloaded, run the installer. There is no key or license control step at this point.
Run CPLEX without limit, even if you're disconnected from your faculty or institution.
If you experience issues and need help then check our developerWorks community, or contact us via our support forum on developerWorks.