The name AvantGo is obviously a critical portion of the company's identity above and beyond its visual attributes. Pronunciation should be consistent. The name should be pronounced with emphasis on the first and last syllables [A-vant-GO]. Incorrect pronunciation includes emphasis on the middle syllable [a-VANT-go].
The A and G are always capitalized: AvantGo. And the name is always one word—AvantGo, not Avant Go.
An incorporated abbreviation should always be used when referring to AvantGo as a corporation “AvantGo, Inc., today announced a new product” but not when referring to a product “She used AvantGo to synchronize her calendar records”.