Complex sentence: He then joined the Softway Group in San Francisco and simultaneously launched his first entrepreneurial venture: with friend Gregoire Gentil he formed Pilot Plus, a software company delivering products on the then nascent Palm Pilot platform.
Split into simpler sentences: He then joined the Softway Group in San Francisco and simultaneously launched his first entrepreneurial venture. With Gregoire Gentil, he formed Pilot Plus, a software company delivering products on the then nascent Palm Pilot platform.