I don't understand how people can actually believe that there is software that is actually 'free'.
Linux has entered the room and not charged a dime now for 35 years. Does it cost someone on the other end creating it
time, money, and resources? Yes it does, but to the end user it does not cost a dime.
Linux is not a single company product like Windows or macOS. The Linux kernel is
open source, and the source code is available for the public to view, study, modify, and redistribute under its license.
Most (not all) Linux distributions are built mostly or entirely from open-source software.
Linux is also heavily used on the server side. Public server statistics are hard to measure perfectly, because CDNs, proxies, shared hosting, cloud providers, containers, and appliances can hide what operating system is really behind a service. Even so, a reasonable ballpark is that roughly
60% or more of publicly measurable web-facing servers use Linux. A broader estimate for internet-facing server infrastructure is probably somewhere around
60% to 80%, depending on exactly what is being counted.
On desktops and laptops, Linux is much smaller but still significant. Traditional desktop Linux is roughly
3% of worldwide desktop/laptop web usage. If ChromeOS is counted because it is Linux-kernel-based, the combined number is roughly
4.5%.
Open source itself is enormous. There are millions of open-source packages and repositories, but most have small user bases. A reasonable estimate is that perhaps 25,000 to 75,000 actively maintained open-source projects have a plausible user base of 10,000 or more people or deployments.
Only a much smaller number have truly massive adoption. If we are talking about direct end-user applications with millions of users, the number may be closer to
50 to
150 major open-source applications. If we also count infrastructure projects, programming languages, libraries, databases, web servers, and software bundled into other products, the number of open-source projects with millions of users or deployments is likely much higher.
Examples of widely used open-source applications include:
7-Zip, VLC, Firefox, OBS Studio, Audacity, GIMP, Blender, LibreOffice, Notepad++, KeePass, and FileZilla.
These are not hobby toys. Many open-source projects are professional-quality programs that take enormous time, skill, testing, documentation, and maintenance. Some are maintained by companies, some by foundations, some by volunteers, and many by a mix of all three. The best open-source software can be every bit as serious and capable as commercial software.
DaVinci Resolve by Blackmagic Design is not open source. It is proprietary software, but the standard version is free for users. It is a massive professional-grade video editing, color grading, visual effects, motion graphics, and audio post-production suite. Many editors consider it a serious alternative to Adobe Premiere Pro, and some prefer it, especially for color grading and an all-in-one editing workflow.
There is absolutely nothing wrong with having a cost and selling software. But on the flip-side there is nothing wrong with using Open Source software if it meets your needs.
Open-source disk imaging tools do exist, but most are not direct replacements for Macrium Reflect, Hasleo Backup Suite, Acronis, or similar Windows imaging products. Tools such as Clonezilla and Rescuezilla can be useful, but they are primarily offline imaging tools. They normally require booting into a separate Linux-based environment, selecting source and destination disks carefully, and restoring from outside Windows