(with some repeats):
Ubuntu/Xubuntu - My main OS for ~ 4 years now.
Chrome/Chromium/Firefox - plus a bunch of free extensions
AdBlock - I probably wouldn't use it if some/many sites didn't use terribly intrusive ads, but unfortunately, it has become a necessity for me.
Teamviewer - awesome - view/control a remote computer. Easy set up. I use this to log into and troubleshoot my mother and my MIL computer, and very occasionally my kids (they are pretty self sufficient at this point). Free for personal use (they make money from corporate use, I guess the free version is just advertising for them)
Libre Office / Open Office - Very good, and getting better every release.
Thunderbird - Email client, from the FireFox/Mozilla people. Very good, but a little quirky in some ways.
Audacity - Excellent audio editor, mostly pretty easy to use and very powerful. Open source on all platforms.
Kazam - Record your desktop to video, great for documenting things you do on your computer. I've recorded my whole set up procedure from a fresh install, so I can recall all the customization steps I do.
GIMP - Photo/graphic editor. Interface a bit clunky, but very powerful, and I've been able to figure out what I need to do.
ClipIt - Can't live w/o this. A clipboard manager, keeps a history of what I copy/paste, so I can go back and re-paste something from a while back. Saves time/effort and getting lost when copy/paste a bunch of little things from several sources to one. I also keep a 'static' list of things, like my email address, so I don't need to retype that all the time.
DigiKam - Photo manager (I also think this is cross platform).
PDF Shuffler / PDF-Mod / Xournal - Allow you to edit/mark-up, sign and type into pdf files. Saves printing, signing, re-scaning docs.
Skype -Gripes me that MS now owns this, but it is a great app when needed. I called home from Europe a few years back, for pennies a minute.
Transmission - Torrent client app - nice when I download new linux iso, I think Libreoffice has a torrent site as well. Way more flexible and reliable than downloading from a single server. I stay completely away from questionable uses.
Various audio/video stuff:
VLC Player, Rhythmbox, Soundconverter (convert audio file format), Asunder (CD ripper), KdenLive (Video editor)
I used to download many of them, but now I use as few "free" online apps as possible.
... “There’s no such thing as a free lunch”. Companies plying their wares on the Internet are not charities. They are trying to make a profit. ...
Of course they're not free, but that's another thread...
We now return to your regularly scheduled "free" app program...
I need to start selling 'broad brushes' , there seems to be a huge demand for them!
It's simply not true that all the free software out there is from someone trying to make a profit (at least not a pure economic profit).
In many cases, a group of developers got together (virtually in many cases) to produce some software that they wanted/needed, but it was too big a job to do for an individual. By releasing it, they get feedback, attention, and draw more developers to keep improving the product. Sometimes they do it so they can have more control over the features, or how it works, than they do with a closed, proprietary program.
So we could say they 'profit' from all this, but is at zero cost to the user.
In some cases the 'free' version of the program exists to gain attention for the paid products. Teamviewer is one example I gave, SKYPE is similar in that basic functions are free, and if you choose to, you can pay for more advanced use (international calls, maybe conference calls are a for-pay option I think). To me, that still counts as 'free', no?
Ubuntu/Xubuntu is another one where the OS is free to the user, but the company that organizes those releases, Canonical, makes their money by providing services to large organizations. Those orgs can choose if they want support, and I benefit from it. It is free for me, and plenty of free support on the forums (better support than you are likely to get from a 'for-profit' organisation).
And in other cases, I think the developer does it as a way to pad his/her resume - great, it is free for me, and they 'profit' in a way that doesn't cost me a penny. Win-Win. I love win-win!
-ERD50