Software doesn't have to cost much, or even anything to be good. There is free stuff out there that is worth looking for. I have gathered a list of software that covers a range of areas, and it falls into one of the categories below:
Open Source - This is generally a community developed application, with a central organizing committee. The source code is available to anyone, they may modify it and use it as they like, and even make copies and give it to others. (And in some cases, they may even sell it...) Open Source does not mean the software is free, you may have to purchase it, but often there is a free version available. All the software listed here does have a free version available, and in certain cases, a paid version as well. Not all paid versions have additional features, but they might: Check the descriptions. Also be aware that for some of the projects listed, there are copycat sites that have similar looking sites but may charge a fee, and/or provide software that has malware embedded.
Freeware - This is software that is as the name implies: free. It does have some restrictions compared to open source such as not having access to source code, may not be able to pass it on, and so forth. But it is free at the current time.
This is my personal list. If you think I should include something else, let me know.