Operating Systems

Windows 95 was developed under the code name 'Chicago'. 'Longhorn' was the code name for Windows Vista, 'Cairo' was a project for a next-generation OS in the early 90s, and 'Texas' was not a primary Windows code name.

Windows 1.0, released in 1985, was a 16-bit graphical operating environment that ran on top of MS-DOS. It was designed to work with the 16-bit Intel 8088 and 8086 processors common at the time.

Xerox PARC developed the graphical user interface concept including clicking icons to run programs in the 1970s (Xerox Alto). Apple's Macintosh popularized this concept later, but Xerox PARC was the original innovator. IBM and Microsoft were not the first.

After Microsoft Windows, Mac OS (macOS) is the most widely used desktop/laptop operating system worldwide, particularly in creative industries, education, and among consumers. Unix and Linux are important but have smaller desktop market share, while iOS is for mobile devices.

This question appears to be from the early smartphone era (approximately 2008-2011) when Symbian was the most widely used smartphone operating system, particularly on Nokia devices. Note that Android eventually overtook Symbian, but in the context of this question's timeframe, Symbian was correct.

Symbian OS was developed by Symbian Limited, a joint venture originally created by Psion, Nokia, Ericsson, and Motorola. While Nokia later acquired Symbian and was its primary user, the OS was developed by Symbian Limited as a separate entity, not directly by Nokia, Blackberry, or SUN Microsystems.

Tim Paterson developed QDOS (Quick and Dirty Operating System) in 1980, which Microsoft purchased and renamed MS-DOS. This operating system became the foundation for IBM's Personal Computer and dominated the PC market through the 1980s. Paterson worked at Seattle Computer Products when he created DOS. Linux was created by Linus Torvalds much later (1991), Unix originated at Bell Labs in the 1970s, and System 7.x was a Mac OS version from the early 1990s.

Do More with Less was Microsoft's advertising campaign slogan for Windows XP, emphasizing enhanced features and efficiency compared to previous versions. Windows Vista (2007) came later, while Windows ME (2000) and Windows 2000 were earlier versions with different marketing.

'Pakistani flu' (also known as Brain) is considered the first IBM PC compatible virus, created in 1986 by two brothers in Pakistan. It infected the boot sector of floppy disks.

OSX/Leap-A (also called Oompa-Loompa) in 2006 is recognized as the first malware specifically targeting Mac OS X. Mocmex targeted Windows. Torpig is a Windows trojan. Rustock.C is a Windows botnet. Leap-A was a significant milestone as it demonstrated that Mac OS X was not immune to malware, though it required user interaction to spread via iChat.

Adobe is a software company (Adobe Systems), not an operating system. Adobe produces software like Photoshop, Acrobat, and Illustrator. Windows, Linux, and macOS (Mac) are all operating systems that manage computer hardware and software resources. Operating systems are system software, while Adobe products are application software.

'Software powers the Internet' was Oracle's slogan, reflecting the company's position as a major provider of database and enterprise software that forms the backbone of internet infrastructure. This messaging emphasized Oracle's role in enabling the digital economy and web-based businesses. The slogan positioned Oracle as essential technology provider rather than just a software company.

The Symbian platform did become open source in 2009. The Symbian Foundation released the source code under the Eclipse Public License, making it freely available for developers.

Sony Ericsson used the UIQ (User Interface Quartz) interface layer on Symbian OS. UIQ was a touchscreen-oriented user interface platform used by Sony Ericsson and Motorola, while Nokia used S60.

The Symbian Kernel was made available under the Eclipse Public License (EPL) on October 21, 2009. This was part of the gradual open-sourcing of different Symbian components. The other dates do not correspond to this milestone.