There are many third-party software choices - freeware, shareware, ad-supported, and Open Source, for example. Open Source software can get complicated if used commercially, but here's what you need to know.

The first thing you need to know as the end-user is that Open Source software is free software or freeware. You might have noticed that some software is advertised as both freeware and Open Source.

The difference is that Open Source software either includes the source code or is available separately for download.

Once you have the source code, anyone can modify the code to suit their needs, then use it personally or distribute it publicly. When you modify source code and distribute it, that is often referred to as a Fork.

You can even modify the code and make it available as a commercial product, but you may discover some limitations. For example, if your code is based on Open Source, you usually can't make it commercially available without also providing the source. This is known as copyleft. Selling software using monopoly or royalties format is frowned upon. You also can't use other logos or names.

Open source gives freedom-loving coders a chance to get together and make something great—together. Open source projects allow everyone to collaborate and share ideas, making sure that all members of the community benefit from each other's work. Plus, open source means that anyone can use the code and customize it to make something unique or make your own "fork" of the original project..

If you see Simplified BSD License or FreeBSD License then most likely you don't need to share your source code. This is known as non-copyleft or permissive.

It's important to know the difference if you want to create a commercial product from source code, especially if you're making major code changes that you want to protect.

Open Source software should contain a copyright statement in the code, which should never be removed.

There are a couple of variations we should discuss that you might have seen that are similar to Open Source according to the Open Source Inititave.

Public domain is a term you are probably familiar with. It refers to work that was never in copyright, to begin with. Because public domain software never had a copyright, it most likely lacks a license or rules. Some jurisdictions don't recognize the public domain. There can be some confusion with public domain software, so you should look for Open Source software if you plan to edit the code.

Creative Commons (CCO or CC Zero) means that the author decided to release his software into the public domain. If you're considering using Creative Commons software, follow the same guidelines as Public Domain.

As you can see, if you want free software, or you want to get the code, the Open Source format is the largest, best, most regulated way to go.

If you have any more questions, refer to the Open Source Initiative FAQ.