Thank you for your purchase of OmniGraffle Professional 4. Today, Wednesday, March 5, we are announcing the official release of version 5, a major upgrade to OmniGraffle. Your purchase qualifies for a free upgrade to version 5. Please note that version 5 requires Mac OS X 10.5, so if you are still using 10.4 you will need to continue to use OmniGraffle 4 until you upgrade.