Lisa is a line of desktop computers that were designed, manufactured and sold by Apple Computer. It was the first mass-market personal computer operable through a graphical user interface (GUI). The Lisa was primarily marketed to individual and small and medium-sized businesses as a groundbreaking new alternative to much bigger and more expensive mainframes or minicomputers such as from IBM, that either required additional, expensive consultancy from the supplier, hiring specially trained personnel, or at least, a much steeper learning curve to maintain and operate.