Complex sentence: Engelbart recruited a research team in his new Augmentation Research Center (ARC, the lab he founded at SRI), and became the driving force behind the design and development of the oN-Line System (NLS).
Split into simpler sentences: Engelbart recruited a research team in his new Augmentation Research Center (ARC, the lab he founded at SRI). The ARC became the driving force behind the design and development of the oN-Line System (NLS).