Operating Systems running on your Smartphone and PC
See too VCU (Virginia Commonwealth University) Operating Systems: Intro and Overview (archived)
The Linux kernel was developed as an open-source operating system in 1991 and posted freely on USENet, a part of the Internet, by Linus Torvalds in Helsinki Finland.
Linux was based on the UNIX operating system that employed the Click here for some of the background to C, the basis of so much hardware and software built during the past 50 years. When compiled, each C language program (with its list of English-like abbreviations and formulae) is converted to machine code under the control of the system clock, which provides timing services. ** End of Page
Browser programs are written mostly in C++
A Browser is different to an Operating System. It is a program (Chrome, Safari, Edge, IE, Firefox) on your computer designed to interpret web page commands.
Web Pages are downloaded from Web Servers
Web Servers ALL send HTML and Javascript commands inside these web pages as a "Front End" to your local browser
Google Search Engine is a program running on its web servers. It is written in Python and C++ and Java
Bing Search Engine running on Microsoft's web servers is written in C++ and C#
Facebook uses PHP, Python, C++, Java, others
Youtube uses C, C++, Python, Java
Yahoo and Wikipedia and Wordpress use PHP
Amazon uses Java, C++, Perl
Whatsapp, purchased by Facebook in 2014, uses Erlang
WeChat is probably written in C or C++ or Java. Cloud Service is perhaps PHP