During his time at Apple Inc., Apple rolled out the Network Server 500 and Network Server 700, in an attempt to enter the high-end server market, released highly confusing Mac OS updates, notably Mac OS 7.5.3 and up to five different variants, introduced the first dual processor Mac, unleashed the PowerBook 1400, terminated development on Copland and Gerschwin, bought NeXT and welcomed back Steve Jobs, started work on Rhapsody, revealed the Twentieth Anniversary Macintosh, and shipped the PowerBook 2400.