When Apple introduced TCP with MacTCP and Open Transport in System 7 in the 1990s, they needed their file sharing protocol (AFP) to run on both TCP and AppleTalk.
Mac OS 9 also featured integrated support for Apple’s suite of Internet services known as iTools (later re-branded as .Mac, then MobileMe, which was replaced by iCloud) and included improved TCP/IP functionality with Open Transport 2.5.
The Open Transport networking architecture introduced standardized PowerPC synchronization primitives.
Based on code licensed from Mentat's Portable Streams product, Open Transport was built to provide the Mac OS with a modern TCP/IP implementation, replacing MacTCP.
Australian Open | French Open | Open University | open source | Rail transport | International Air Transport Association | U.S. Open | Wacken Open Air | Department for Transport | The Open Championship | U.S. Open (tennis) | Pipeline transport | London Transport | Secretary of State for Transport | Ministry of Transport | Baby transport | Transport for London | transport | All England Open Badminton Championships | U.S. Open (golf) | Open Source | Open-pit mining | British Transport Films | 2006 Australian Open | Transport Layer Security | Regie voor Maritiem Transport | Open Software Foundation | Indira Gandhi National Open University | British Transport Commission | Lamar Hunt U.S. Open Cup |