Years ago, there was a vigorous debate about whether open source software (also known as Free (as in speech) Software, software libre and freedomware) could ever compete with proprietary software. Usability, the traditional handicap of open source, is a problem that is gradually being solved.
Migrating to open source is not difficult; much open source software is available on Windows, so you won't have to switch to Linux if you don't want to. If you want to save money and free yourself from vendor lock-in, then start making the switch yourself.
Steps
Try out LibreOffice or OpenOffice, open source office suites which are available for many platforms (including Windows). They come with a word processor, spreadsheet, a presenter (akin to PowerPoint), an illustrator, and a database manager. Alternatively, if you only need a word processor and spreadsheet application, AbiWord is a fast and lightweight word processor and Gnumeric is its counterpart spreadsheet program. LibreOffice comes installed on many Linux distributions.
If you have been using Microsoft Outlook for a while, there is an e-mail client called Zimbra that you can consider having and it supports almost all of the e-mail providers. It works on Windows. Another e-mail client to consider is Mozilla Thunderbird.
Mozilla Lightning and Sunbird provide shared calendars, and Evolution, also available for Windows, is a "groupware" application that works with Novell GroupWise and some versions of Microsoft Exchange Server.
Switch to an open source web browser. Firefox is a free, cross-platform web browser that offers greater privacy and prevents pop-ups, spyware and viruses. It is also customizable to large degrees. Google's Chrome browser renders pages very fast, though it includes some proprietary (non-open-source) components. Try out Chromium, which is an open-source version of Chrome.
If you are after an FTP client, FireFTP (a Firefox add-on) will do the trick within your browser; FileZilla is a cross-platform FTP client with many features.
Use the GIMP (GNU Image Manipulation Program) which is a free alternative to costly raster image processing and editing programs. It is available for Windows as well as Unix-like systems. There are many GIMP tutorials available on the Web; wikiHow has a category devoted to this.
Install Inkscape if you want a full-featured and easy-to-use alternative to the likes of CorelDraw.
Make use of the VLC media player, which plays almost all common formats of videos without the need for downloading additional codecs.
Install CDex if you need an excellent and easy-to-use, although Windows-only, CD ripping program.
Use Content Management Systems like Drupal, Joomla, and WordPress for starting your own web sites. You don't need to know any HTML, PHP, or any other language to manage your own websites. There are plenty of free themes and add-ons available on the Web for these, too.
Install some open source games. This is one area in which open source still has not beaten the proprietary software world. Nevertheless, there are still some excellent and fun projects out there. Sauerbraten is an incredibly fast-paced, fun and compact first person shooter (and AssaultCube is a genetically-related, slower-paced version with more "realistic" weapons), and Freeciv is an empire-building strategy game. Nexuiz is a big download, but also a great first-person shooter. BZFlag, a multi-player tank game, is one of the most downloaded games on SourceForge.net with a very active community.
If you're ready to take the plunge, you might want to check out the world's most famous open source product: the Linux operating system. These days, it is a very viable alternative to Windows and runs on almost all hardware out there, including obsolete hardware on which current versions of Windows will run poorly or not at all. There are also the various open source BSD projects. Also, Google's Android smartphone and tablet operating system is, and its upcoming Chrome operating system will be, open source.
Tips
Avoid services that use copy protection on the music you download. This is not just awkward; this makes it impossible (and in some jurisdictions, illegal) to play the music that you paid for in anything but the software that the music service sees fit to support—which excludes open source software altogether. Services such as eMusic.com and Amazon will allow you to legally buy and download music in the universally-supported and DRM-free MP3 format, and so will not lock you into a single vendor. iTunes is also now DRM free and uses the AAC file format; which is open source, free to use and can be used on many music players and with player software. Be aware though that many of these services (such as Amazon, and iTunes) do embed your account information which can be used for your prosecution should you allow others to download your music through file sharing.
Learning to use free software can not only save you money but can save you time and help you do more in the long run.
It's extremely easy to find just the right software and keep it up to date. Because nothing is expected in return beyond what you may choose to contribute, everything is available on the Internet. A free software distribution such as Ubuntu, Fedora, Debian or Red Hat installs with a basic set of programs and lets you choose pretty much anything from the operating system's built-in package selection menu to have installed, kept updated essentially automatically, and, if you don't like it, easily removed.
The skills you develop won't become obsolete. Because anyone can pick up where another left off in developing free software, important programs and components are generally maintained and improved for many years until, and often after, something fundamentally better comes along. There's no "upgrade treadmill" of popular programs falling into obsolescence through incompatibilities or hobbling of programs, both of which can cause many problems aside from expense. Much of the core functionality of the free operating systems that now run everything from smartphones to supercomputers today traces to the the original UNIX of the 1970s[1]; much of the core programming code, to GNU[2] and other free software projects started in the 1980's, and, of course, to the Linux[3] kernel, started in the 1990's. Compatibility with earlier programs' data, with multiple operating systems (particularly free ones) and with multiple hardware architectures tends to be excellent.
Computer software and skills gain value through network effects.[4] This is particularly true of free software because users can not only help each other learn to use it and share data most conveniently but actually make the software itself better. So, don't just get started yourself, help others get started too!
Consider contributing to open source projects. You don't have to be a software developer to do this. If you are a good writer, consider writing documentation (which many, if not most, open source projects need badly). If you are good at game artwork or 3D modeling, consider contributing your work to an open source game project. Even if you're only good at telling whether software is working properly or not, start filing useful bug reports with the authors.
Most distributions are shipped in many languages and you can customize your desktop with your local language. Check if your language is available in GNOME translation project. Knoppix, a distribution of Linux that boots from CD ROM without using the hard disk drive (a "LiveCD"), was developed by Klaus Knopper originally in German.
Join a user forum like LinuxQuestions.org or a forum for the respective application or Linux distribution. There are a lot of people out there willing to help beginners. When asking for a solution to the problem, always try to be concise and informative. Give as much information that you know about the problem and about your computer configuration. Be polite and patient and someone will surely help you. When you notice someone with the problem you are sure that you know how to solve help him out.
On the other hand, if you are a developer and want to do the most you can for the open source and free software world, you might want to look at the Free Software Foundation's list of high-priority projects.
"Shop" around. Try more than one different program, as more often than not, there is something that suits your needs more than the first program you found.
Choosing to run as much open source software as possible is a political choice for some. People may choose to use such software as a protest against software with very restrictive licensing; these people usually prefer and use the term "free [as in freedom] software", and align themselves with the likes of the Free Software Foundation. These people prefer to run free software because of the principles and ideals involved, regardless of its technical merits as compared to closed source software. Bear this in mind when participating in open source communities. This is a divisive issue in the free software/open source community; raising it (for example, by advocating proprietary software) will be seen as impertinence and tactlessness at best, and trolling at worst.
A popular and user-friendly Linux distribution is Ubuntu. Boot from the LiveCD to see a full working version, with no install needed!
If you are running Linux, you can install some of your Windows applications (setup files) with WINE.
Try searching on Osalt.com for a commercial program you want to replace. You give it the name of a commercial software program, and it suggests open source alternatives you can use instead.
To do something new, search freshmeat.net's directory of open source software, or, if you're using Linux, the integrated software installer's directory of program "packages".
One excellent area to find open source software is, of course, Wikipedia! For example, there is a list here of a lot of excellent software.
Warnings
While open source software has made massive progress in usability in the last decade, some of it can still be difficult to use and have unintuitive, inconsistent, poorly organized, or no documentation.
When you want to deploy Linux for your small or mid-sized company, make use of the help and support from the respective distribution officially by paying them. You need some experience to configure and set up networking servers.
Back Up Data periodically; before major software changes, preferably; and before an operating system change or upgrade, always.
Things You'll Need
A computer.
An Internet connection. The faster the better; nearly all open source software is primarily available online.
Related wikiHows
How to Get Free Software
How to Start a Wiki
How to Create a Free Wiki With Wikia
How to Contribute to Open Source
How to Convert PowerPoint to Flash Using Open Source Tools
How to Secure a Linux Server
Sources and Citations
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