Every discipline has its must-have software applications that drives sales of the underlying platform, also known as “killer apps”. Windows benefits from many killer apps, most notably from PC games and business software. As far as the general home user is concerned it’s easy to identify members of the iLife suite, such as iPhoto and iMovie, as killer apps for OS X. Macs have always had a strong following in the world of scientific computing, with recent popularity being driven mainly (in my opinion) by OS X’s ability to run the wealth of existing scientific applications developed for UNIX systems. A while back I predicted that a number of killer scientific apps would begin to appear for the OS X platform due to the fact that Apple gives their developer tools away for free. In addition the Cocoa API (used to develop native OS X programs) is so elegant and well documented that an individual with even the smallest bit of technical ability is able to produce a simple application using Applescript Studio. Aside from the efforts by the brilliant developers at Mekentosj my prediction is thus far proven incorrect. Of course my personal interests lie in the field of Bioinformatics so it’s very likely that I’ve missed some great killer apps in other scientific domains. If you’ve switched to Mac to use a particular killer app, or would refuse to leave the Mac platform because of a killer app, please post a comment to this story so we can highlight these applications and keep a running list for those curious about the best scientific computing platform around.