Version 12.8 of CPLEX Optimization Studio is available for on Passport Advantage for commercial users, through the Academic Initiative program for academics and students, and as a trial version for all. Here are some of the most prominent changes:

• Performance improvements on a wide range of problem types
• OPL and the IDE available on MacOS.
• New callback framework in CPLEX, to avoid disabling dynamic search, and make sure that callbacks don't interfere with the CPLEX search when not necessary.

Additional information can be found in this blog post, and in the release notes.