Operating systems written in C++ programming language.

Apple – OS X
Few parts of apple OS X are written in C++ programming language. Also few application for iPod are written in C++.
Microsoft
Literally most of the software are developed using various flavors of Visual C++ or simply C++. Most of the big applications like Windows 95, 98, Me, 200 and XP are also written in C++. Also Microsoft Office, Internet Explorer and Visual Studio are written in Visual C++.
Symbian OS
Symbian OS is also developed using C++. This is one of the most widespread OS’s for cellular phones.

Adobe Systems
All major applications of adobe systems are developed in C++ programming language. These applications include Photoshop & ImageReady, Illustrator and Adobe Premier.
Google
Some of the Google applications are also written in C++, including Google file system and Google Chrome.
Mozilla
Internet browser Firefox and email client Thunderbird are written in C++ programming language and they are also open source projects.
MySQL
MySQL is the world’s most popular open source database software, with over 100 million copies of its software downloaded or distributed throughout its history. Many of the world’s largest and fastest- growing organizations use MySQL to save time and money powering their high-volume Web sites, critical business systems, and packaged software — including industry leaders such as Yahoo!, Alcatel-Lucent, Google, Nokia, YouTube, Wikipedia, and Booking.com.
Alias System – Autodesk Maya
Maya 3D software was originally developed by Alias System Corporation and was later carried over by Autodesk. Maya 3D software, now a days is widely used in computers, video games, television. It is a powerful, integrated 3D modelling, animation, visual effects, and rendering solution.

12D Solutions
12D Solutions Pty Ltd is an Australian software developer specialising in civil engineering and surveying applications. Computer Aided Design system for surveying, civil engineering, and more. 12D Solutions clients include civil and water engineering consultants, environmental consultants, surveyors, local, state and national government departments and authorities, research institutes, construction companies and mining consultants.