Chicago (codename)

Chicago (codename)

Chicago (codename) was the internal Microsoft project that produced an early consumer-oriented operating system prototype leading to Windows 95. Conceived in the early 1990s, Chicago unified ambitions from earlier Microsoft efforts such as Windows 3.1, Windows 3.11, and the aborted Cairo (operating system) initiative, while integrating influences from MS-DOS and contemporary competitors like Apple Macintosh and IBM PC DOS. The project assembled teams from Microsoft Windows NT and application groups to target both retail users and OEMs.

Background and development

The Chicago initiative stemmed from Microsoft's response to shifting markets dominated by Intel CPU advances, the rise of graphical user interfaces exemplified by Apple Lisa and Mac OS, and pressure from IBM and Digital Research. Key figures and organizations included executives at Microsoft, engineers familiar with MS-DOS, and designers who had worked on Windows 3.0 and Windows for Workgroups 3.11. Chicago sought to merge features from the Windows 3.x line with anticipated technologies from Cairo (operating system) and research from the Windows NT team. The project also factored in partnerships with OEMs such as Compaq, Dell, and HP, and hardware directions from Intel with its Pentium microprocessor. The project timeline intersected with industry events like COMDEX and the emergence of Microsoft Office as a dominant application suite.

Features and architecture

Chicago aimed to deliver a 32-bit-ready, user-friendly shell while retaining compatibility with MS-DOS applications and Win16 programs. Architecturally, it explored hybrid models combining components from Windows 3.1X and ideas from Windows NT: preemptive multitasking concepts from the Windows NT kernel were weighed alongside cooperative multitasking legacy from Win16. Planned UI components referenced innovations found in Program Manager and later the Start menu concept, with desktop metaphors familiar to users of Mac OS and AmigaOS. File system considerations involved support for FAT16 and aspirations toward VFAT long filenames, influenced by industry standards such as ISO 9660 for optical media and interoperability with Novell NetWare and LAN Manager networking stacks. Compatibility layers were designed for popular software including suites like Microsoft Office, browsers emerging from projects like Netscape Navigator and early Internet Explorer prototypes, and multimedia APIs similar to DirectX precursors. The project evaluated localization for markets served by platforms like OS/2 and assessed device driver models to support printers from Epson, HP, and display adapters from ATI Technologies and NVIDIA beginnings.

Release, testing, and cancellation

Microsoft released multiple internal and OEM preview builds of Chicago to solicit feedback from partners including Intel, Compaq, and Acer. These builds circulated at industry gatherings reminiscent of COMDEX demonstrations and were tested against applications from vendors such as Adobe Systems, Symantec, Corel Corporation, and Borland. Public beta cycles later branded under Windows 95 incorporated lessons learned from Chicago prototypes. Some Chicago builds were showcased in magazines covering products like PC World and Byte (magazine), and were scrutinized alongside competing platforms such as OS/2 Warp and BeOS. While Chicago itself was not cancelled outright, the codename was retired as milestones coalesced into the commercial Windows 95 release; some envisioned features from Chicago were deferred or reworked as part of the formal product launch and as separate initiatives such as Windows 98 and Windows NT 4.0.

Legacy and impact

Chicago's development directly influenced the consumer shift represented by Windows 95, which introduced mainstream features including the Start menu, taskbar, and improved plug-and-play support that Chicago prototypes experimented with. The project shaped Microsoft’s approaches to backward compatibility for Win16 applications and informed strategic relationships with hardware partners like Intel (for Plug and Play cooperation) and OEMs including Compaq and Dell. Chicago's integration of emerging networking and multimedia ideas fed into subsequent Microsoft technologies such as DirectX, Internet Explorer, and enhancements in Windows NT branches. Industry reactions connected Chicago-era work with competitive outcomes involving Netscape Communications Corporation and the later Browser Wars, as well as legal and regulatory scrutiny of platform bundling exemplified by cases involving United States v. Microsoft Corporation. Personnel and research from the Chicago timeframe contributed to later Microsoft products like Windows 98, Windows Me, and enterprise-facing Windows 2000.

Versions and codenames within the Chicago project

During its life cycle, Chicago encompassed numerous internal builds and nicknames used by development, testing, and OEM engagement teams. Notable internal milestones included build numbers circulated to partners and preview groups, which preceded public beta waves associated with what became Windows 95. Parallel Microsoft initiatives such as Cairo (operating system), Chicago 95 prototypes, and work from the Windows NT team overlapped in concept and personnel, while later retail editions adopted different marketing names. The project's iterative builds influenced versioning for successors like Windows 98 and Windows 2000, while related experiments seeded features in applications from Microsoft Office and system components used by partners including AOL and Earthlink.

Category:Microsoft projects