Service Packs are free. They contain changes, enhancements and fixes since the release was first shipped. *
You need the service pack if it is newer than the version you are running. You can tell if the service pack is newer if the build number on the 'What's in the Service Pack' page is higher than the build number in your software.
* If you run a special "corporate" edition of SIMUL8 that has features unique to your company, don't use these upgrade files - your company's special features will go away! If in doubt talk to your company's internal SIMUL8 Team or email us at