Windows CE in the context of "Jornada (PDA)"

Windows Mobile 2003, originally codenamed "Ozone", is a member of the Windows Mobile family of mobile operating systems, released on June 23, 2003, succeeding Pocket PC 2002 and Smartphone 2002. It was the first Microsoft mobile OS to be called "Windows Mobile" and is based on Windows CE 4.2.

Windows Mobile is a discontinued mobile operating system developed by Microsoft for smartphones and personal digital assistants (PDA). Designed to be the portable equivalent of the Windows desktop OS in the emerging mobile/portable area, the operating system is built on top of Windows CE (later known as Windows Embedded Compact) and was originally released as Pocket PC 2000.

Microsoft introduced the Pocket PC keyboard-less PDAs in 2000, with Pocket PC 2000 being the software. It was based on version 3.0 of Windows CE, the operating system originally developed for the Handheld PC in 1996. The next versions were Pocket PC 2002 and Smartphone 2002, the latter of which would power a new category of keypad-based cell phone devices named Smartphone. With the release of Windows Mobile 2003, the software was rebranded to a single "Windows Mobile" for both Pocket PCs and Smartphones, and to connect the brand with its desktop counterpart. Support for SH-3 and MIPS processor architectures were dropped, focusing only on ARM. In the next major release, Windows Mobile 5.0 in 2005, Microsoft unified the separate developments of Pocket PC and Smartphone software into a single Windows Mobile codebase. Data could be synchronized with desktops using ActiveSync software, and later using Windows Mobile Device Center.

Internet Explorer (formerly Microsoft Internet Explorer and Windows Internet Explorer, commonly abbreviated as IE or MSIE) is a retired series of graphical web browsers developed by Microsoft that were used in the Windows line of operating systems. While IE has been discontinued on most Windows editions, it remains supported on certain editions of Windows, such as Windows 10 LTSB/LTSC. Starting in 1995, it was first released as part of the add-on package Plus! for Windows 95 that year. Later versions were available as free downloads or in-service packs and included in the original equipment manufacturer (OEM) service releases of Windows 95 and later versions of Windows. Microsoft spent over US$100 million per year on Internet Explorer in the late 1990s, with over 1,000 people involved in the project by 1999. In 2015, Microsoft Edge was released to succeed Internet Explorer 11 as Microsoft's primary web browser. New feature development for Internet Explorer was discontinued the following year year, and support for the browser officially ended on June 15, 2022, for Windows 10 Semi-Annual Channel (SAC) editions.

Internet Explorer was once the most widely used web browser, attaining a peak of 95% usage share by 2003. It has since fallen out of general use after retirement. This came after Microsoft used bundling to win the first browser war against Netscape, which was the dominant browser in the 1990s. Its usage share has since declined with the launches of Firefox (2004) and Google Chrome (2008) and with the growing popularity of mobile operating systems such as Android and iOS that do not support Internet Explorer. Microsoft Edge, IE's successor, first overtook Internet Explorer in terms of market share in November 2019. Versions of Internet Explorer for other operating systems have also been produced, including an Xbox 360 version called Internet Explorer for Xbox and for platforms Microsoft no longer supports: Internet Explorer for Mac and Internet Explorer for UNIX (Solaris and HP-UX), and an embedded OEM version called Pocket Internet Explorer, later rebranded Internet Explorer Mobile, made for Windows CE, Windows Phone, and, previously, based on Internet Explorer 7, for Windows Phone 7.