I think that the easiest way to do this is to compress the current installed version in your Applications folder and then install the other version before expanding (unzipping) the existing one. I think this should allow you to run both at once. It looks like this is the recommendation made in the guidelines posted by Adam Twardoch here:

http://forum.fontlab.com/index.php?topic=8561.0

An even easier way would be to buy a Windows machine…

We have posted today new pre-release builds 4692 of FontLab Studio 5.1.3 for Mac and 5.2 for Windows. Quite a few bug fixes, finally including a fix for the RoboFab UFO importing problem!

Best,
Adam

In other words, it’s not ready for prime time yet, but what the hell.

BTW, 2013 is fast approaching, you know. For that matter, 2012 is almost gone: whatever happened to DTL Kernmaster 2012? I’m due a free upgrade…sometime in this lifetime, I hope…

We believe that FontLab Studio 5.1.3 Public Preview build 4692 is better than any previous version of FontLab Studio 5.x for Mac, but we cannot yet confirm and guarantee it. This is why the build has the "beta status". The officially released, confirmed to be stable at the point of its release, is version 5.1.2 build 4447.

Between build 4447 and 4692, we released a number of intermediate builds in which, unfortunately, as it turned out, some things got fixed yet others got broken.

Currently, we believe that we have fixed all the things that got broken after build 4447 — and that’s build 4692. It includes all the "good fixes" after 4447, as well as all the "fixes of the things that got broken".

(In addition, I can say that we have taken some organizational steps that we believe will prevent such things from happening again.)

So far, the feedback on build 4692 has been very good. We at FontLab would really like to thank all the people who have submitted their problem reports and participated in the discussions on our forum over the course of the last 15 months.

We've come a long way since build 4204, our developers fixed over 500 problems, and — again — we believe that build 4692 already is the most stable FontLab Studio ever to exist on Mac OS X.

Many thanks,
Adam

> whatever happened to DTL Kernmaster 2012

All I can say is that I sympathize with our colleagues at DTL and URW++. We at FontLab know that developing complex software applications is hard work, and we've learned it the hard way — especially recently. Despite the fact that we've had the largest team of developers and internal QA testers ever — it took us more than two years of full-speed work to move from FontLab Studio 5.0.4 to the current public preview build of 5.1.3.

So I keep my fingers crossed for the new version of DTL KernMaster!

Best,
Adam