Free Software - (Mostly for Windows PCs)

Web Browsers
These are the main ones but now there are many more out there with special features. The Safari browser is built into Apple MacKintoshes but a spurious Windows version was never much good and Apple dropped it. They nearly all use the 'Chromium' engine these days at their core, which was developed by Google for the Chrome browser. The most prominent odd one out is Firefox, which might still use the 'Gecko' engine, as did Opera at one time.

By the way, web designers ought to keep in mind that people use mobile devices and smart televisions for web browsing. One local website tells me that my smart tv has an old browser and won't support it, denying me access to its services. They have not heard of 'The customer comes first.'
Key: W = Windows, M = Mac, L = Linux.

• Edge - (Windows only)
  There is no download for this one as it comes with Windows 10 and above, with the old Internet Explorer being abandoned. It is quite integrated into the system too. It does a lot but can be annoying. I find it a bit clunky, as they tried so hard to make it user-friendly that the interface is dumbed down. Eg. Its PDF reader doesn't remember if you prefer a two-page layout. You have to click three times to get there, every time. You can't easily change the default settings.
• Firefox - (W, M, L)
  Once the most popular browsers for many years and still has many enthusiasts. It also appears to screen out dodgy websites better than some of the others if you adjust the settings to maximum safety. This one has a long pedigree, having followed on from the once-popular Netscape browser which had been wiped out by Internet Explorer being bundled with Windows (that's a long story involving litigation). One of few browsers not using the Chromium engine. Well-recommended.
• Chrome - (W, M, L)
  Google's own web browser based upon the Chromium engine - but do really you trust Google to not record all of your browsing activity. They are a bit sneaky, you know. The latest version supports the use of a Chromecast dongle on your TV, which lets you 'transmit' your computer's webpage, youtube, etc. on to the telly.
• Opera - (W, M, L)
  Originally from Norway, this used the Gecko engine. It was the first browser to use tabs and one of its great features was that you could continue a browsing session where you left off previously, while none of the others did so at the time. It started as a paid-for app but with a free version showing advert banners at the top and it was my great favourite for many years. Then it went free, the banners disappeared and it became a really good browser for a long time. Then it moved to the Chromium engine and was dumbed down, losing several of its best features. A Chinese company bought it. Opera's updater runs silently in the background. Unusually, it has a built-in but limited VPN which is really a redirection.
• Vivaldi - (W, M, L) My top choice.
  After the Chinese company took Opera over, one of the original Opera design team created Vivaldi along the same lines as Opera from scratch and kept many of the older Opera features. It was slow to become noticed and remains a backwater browser but it is still worth trying. It now uses the Chromium engine like most of the others. Vivaldi turned into one of the best browsers out there and it is frequently updated. Read their blog about how Microsoft tried to prevent people from using Vivaldi.

Searching

• SearchUK - You can search the UK search engines separately.
• Dogpile - Or aggregate them in one go. Now wash your hands.

General Help With PCs

• Britec09 on Youtube - Offers a lot of ideas and help.

For Pleasure
Okay, so I'm boring ...

• Kindle Reader for PC - (Win only)
  Nice freebie from Amazon to read their popular e-book format, with dictionary built-in.
• Stellarium - (W, M, L)
  Planetarium software for Windows, Mac and Linux. A mate who knows about these things says it is very good. I've tried it on both Ubuntu Linux and Windows 7 and it works very well. It certainly has the 'Wow Factor' if you like star-gazing. Just a minor bug, though. If you use Window's mouse trails, the cursor arrow will disappear. You can still use it but it requires a bit of guesswork.
• NASA's Eyes - (Windows 7+ only)
  More than another planetarium, according to Computer Active magazine, it is the 'simulator to end all simulators'. It updates from NASA every time you open it, although it will continue to work off-line after you have connected. Not yet tried but it looks as though you can amble around the solar system or choose any of the NASA missions and go along for the ride.
• Gutenberg Project (Link) - Not a program - Download free books. Mostly old classics.
• Archive.org (Link) - A USA repository archive site of books, films, software and more, with plenty of historic material from the UK. Mostly copyright-free.