Well, it's been a while since the last release of the Seam Carving GUI. Brain_Recall recently put some more work into makeing CAIR more multi-threaded when possible claiming performance improvements of 30-70%.
Some of these changes were in the 1.10 release, but unfortuntately, that broke the Mac OS X build as he used some posix semaphores (which apparently are not supported in Mac, although seemgly compile). So for the 1.11 update I ported CAIR 2.19 to the mac by using some cross-platform trickery.
Also, I used the opportunity to make ramses build scripts (another project of mine) for the project and Qt 4.5.2 for msvc from qt-msvc-installer (yet another project of mine). The results are that you gain the benifit of the MSVC 2008 optimizing compiler for more speed and a sparkley, shortcut making windows installer for more convenience.
Get the latest now and experience the speed improvements from multiple fronts.