- Ambassador – A simple IRC client forked from legacy Firefox addon ChatZilla.
- Brave – A privacy-focussed web browser with automatic ad & tracker blocking.
- LibreWolf – A similar concept browser based on Firefox rather than Chromium.
- Vivaldi – Another browser from the creators of Opera. Extremely customizable.
- Flashpoint – A large-scale Flash preservation project. A client allows you to search, download, and run a massive collection of stuff.
- f.lux – Automatically adjusts the color temperature of your screen at night. (I dunno about its claims about helping you sleep better or whatever, I just think it's nice.)
- foobar2000 – Simple audio player with several plugins for playing emulated game soundtrack rips. Can also mass convert files into another format.
- GIMP – Free Photoshop alternative.
- MIDIjs – A midi player for your website?
- PNGGauntlet – Compress your PNGs (by 50% or more!) before uploading to save on storage/bandwidth/whatever. (All my personal PNG files on this site were ran through this.)
- qBittorrent – Stop using uTorrent.
- Real-Time Corruptor – Corrupt your video games. (As popularized by Vinesauce.)
- Rockbox – Custom firmware for older MP3 player devices.
- Sumatra PDF – Just a nice, basic PDF/CBZ/etc reader.
- VLC media player – A very robust media player that supports many formats.
- Webamp – Winamp for your web browser. Install it on your site if you want.
- yt-dlp – Download YouTube videos, or pretty much any other kind of video from pretty much any other site. Runs on command line, so it can be tricky to use.
- YY-CHR – A tile viewer for digging through the graphics of old game roms. (Partly used for my NES CHR page.)
- The Ultimate Oldschool PC Font Pack – Classic pixel bitmap fonts for modern use.
- bsnes-plus – SNES emulator. A fork of the incredible bsnes, with some added debugging functionality. (R.I.P. Near)
- Dolphin – GameCube/Wii emulator. Tons of support. Truly a triumph in community effort.
- DuckStation – PS1 emulator. A surprising new project that's super fast, simple, and lightweight. Offers dynamic resolution options, including widescreen in some cases.
One to watch. Development has ceased but it's still extremely good.
- FCEUX – NES emulator. I dunno, there's probably better options out there, but this is the one I use.
- FinalBurn Neo – Arcade emulator. Famous for NeoGeo and CPS1/CPS2, but seems to support a bunch of random stuff now. The official successor to "Alpha".
- melonDS – DS emulator. Includes uprezing options, which can really make those low poly 3D games pop.
- Mesen – NES/SNES/etc emulator. Also seems pretty good.
- mGBA – GBA/GB emulator. It can uprez "Mode 7" type graphics, which really cleans up games like F-Zero and Mario Kart.
- PPSSPP – PSP emulator. Sort of Dolphin-esque in its level of polish. Quite nice.
- Ruffle – Flash Player emulator. Adopted by a number of familiar sites after Flash was killed off. And you can embed it on your site. Far from complete, but making strong progress.
(some ppl still use this right?)