SpotOn goes mobile with this downloadable program. The Revolutionary SpotOn Ballistic Match Technology program allows you to precisely and accurately match whatever cartridge you are shooting to your Nikon riflescope. This program is as easy as 1-2-3 but can provide the long range enthusiast with as much detail as they would require. Includes most of today's popular ammo and is constantly updated so you can stay SpotOn Nikon Spot On System Requirements MAC: Mac OS X 10.4 and higher, Power PC G4/G5 or Intel Processor, At least 1GB RAM, 15MB available hard disk space. Sun Apple Java Runtime Environment (JRE) 5.0 or higher. (Apple Computer supplies their own version of Java - Use the Software Update feature available on the Apple menu to check that you have the most up-to-date version of Java for your Mac. PC: Windows 98, NT, 2000, ME, XP, Vista, 7, Intel or AMD Processor at 1GHz or faster, At least 1GB RAM, 15MB available hard disk space. Sun Java Runtime Environment (JRE) 5.0 or higher. (Free download/update from: http://www.java.com/en/download.