The term open source (OS) arose in late 90s; although, much of modern internet infrastructure predated and evolved from active code sharing between researchers after the dawn of modern computing age. It is difficult to trace its origins due to space constraints, but suffice to say that it arose out of ambiguity in fair use doctrines, with significant access barriers for community to examine source code or modify it. Interestingly, these ideas have spawned crowd sourcing for open source hardware, notably robotics and influenced scientific publishing for open access traditionally encumbered by copyright protection. Over the time, several unique and hybrid models of licensing have evolved for implementation.
One of the most prominent examples of OS software collaboration is development, porting and extensive deployment of Linux kernel. It proudly runs on the top ten fastest super computers and nearly the entire Web infrastructure. Linux geared towards desktop usage has X Window System (notably Gnome, KDE, XFCE) and package management systems (Debian, Arch Linux, Red Hat etc.) collectively called as a Linux Distribution or a Distro. Importantly, Linux is inherently secure, scalable as well as free from any vendor lock in. However, this write up does not address the naming controversies between GNU or Linux.
This reviewer started with BASIC and COBOL on 486 based processors and migrated to Microsoft Windows after desktop computing became affordable. MS Windows was and still remains a magnet for viruses, trojans and other malicious software despite its advertised firewalls and virus scans for security. This being closed source, zero day exploits targetting weaknesses in the code base remain common for MS Windows. Additional security impacts hardware performance leading to a frustrated user experience, and this reviewer has faced endless reboot cycles for installing new software! Further, a new release from Microsoft often warrants a more expensive hardware because of bloated code base size.
From minimalist to full fledged distros, users would be spoiled for choice. This reviewer endorses Debian Linux (and its derivative Linux Mint based on Ubuntu) as the default desktop choice due to its extensive software repositories and efficient packaging system. Although rpm based distros (like Open Suse) remain excellent alternatives, it boils down to personal preference. He finds it extremely easy to install personal packing archives (ppas) for Linux Mint; although one can also compile it straight from the source tarballs.
For Windows users looking to migrate to Linux Mint, its easy to create bootable USB