Open-source? Freeware? Which is it? Some people frequently interchange the terms as a generic way to say that a piece of software costs nothing to download or use. I mean, it's all free, right?
Open-source software has as much to do with freeware as an apple has to do with an orange. Both are fruits, but each offers a different enough of a texture and flavor to render it completely unique from the other. You cannot, and should not, confuse open-source software with freeware, as there can be grave consequences for such a fatal misstep. Ok, so maybe not grave. But you can get slapped with a lawsuit depending on how you're using the software, and that's certainly not fun. But we're not here to confuse you; we're here to help you.
Here's the deal. When you use a piece of open-source software, you're not getting free reign to do whatever you want with the program. Not explicitly , that is. While the open-source movement does encourage innovation and spin-offs (otherwise known as forks), all of your tinkering and usage of a particular piece of software is governed by the software's licensing agreement. You agree to the agreement once you start using the program, and it can be revoked if you fail to adhere to its stipulations.
For example, consider MySQL: developers can use MySQL all they want under an open-source GPL liscence . Depending on how much of the created work uses MySQL parameters (which is specified in the license for a legal mind to figure out), then the developer has to slap a GPL license on the created work. In essence, use too much open-source code under a "you can modify this as you see fit" license, and you have to open your work to the same amount of modification. This ramifications this has for a company are simple: If you open-source your code, than your competitors have every right to take exactly what you've done and either sell it as-is (if the license allows it), or tweak it and make it better than you.
Some companies don't want that. In the case of MySQL, developers are free to purchase a commercial license for the database. This allows them to create their works using MySQL without having to open their code to others. And if you think, even for a second, that these licenses are unenforceable, think again. The case of Jacobsen v. Katzer is a recent example of a case that went a long way to strengthen the power of open-source licensing agreements. In short, Katzer's company developed a commercial application using parts of Jacobsen's source code, but not attaching his license to the project. Jacobsen sued, and a U.S. Court of Appeals (in tossing the case back for review) noted that the license was fully enforceable as a copyright condition of the work.
In short, obey the license!
Unfortunately, the concept of "freeware" is not as cut-and-dry, and we only have ourselves to blame for that. The word has two meanings: software that is free in price, and software that is free in usage. Using the former, we could indeed classify open-source software as freeware. However, the latter would not apply, given the lengthy discussion of licensing agreements we just entertained.
Freeware that is "free in usage" could be considered public-domain software. You're free to take the software and do whatever you want with it. You can modify it, you can sell it, you can wear it on a hat--the choice is entirely yours. Freeware can also refer to software on the other side of the spectrum. This software costs you nothing to download or use, but the creator still retains the copyright to the work. You might not be permitted to make any modifications whatsoever depending on the distribution terms, nor might you be able to turn around and sell the software either standalone or as part of a larger bundle package.
Confused? You should be. Consider "freeware" to be a giant lake, and open-source software is but one lily pad on the water. The Free Software Foundation spells it out in greater, more confusing detail. Here's a quick rule-of-thumb: whenever you download a program that you're intending to do more with than use on your PC, check the distrobution or licensing agreements. Don't trust the misnomers of "freeware," "free," and even "open-source," because different people mean different things with each word. And do your best to avoid using the term freeware, easy as it may be. Software that's free to download might not be the freeware that you think it is.