Adobe Flash

Adobe Flash is a program originally created by FutureWave Software (?-1996) and Macromedia (1996-2005), then Adobe (2005-present). It can make great stuff like animations if used with some other programs like After Effects, Photoshop and Vegas Pro. It is availible as Adobe Animate now and is used today, but people export their animations to .mp4 now because of Flash's EOL. Thanks to programs like Swivel (By Newgrounds), you can save Flash animations by converting them to video (make sure to only use Swivel, it's much better.)

Website
https://www.adobe.com/products/animate.html - buy it or start a free trial

https://thehouseofportable.com/2826/adobe-animate-cc-2019-portable/ - for free! (No crack, portable, might have to whilelist the program in the antivirus in order for it to work/load, though.)

Which one do I need?
It doesn't matter if it's outdated (unless its Flash Professional 8 through Futuresplash Animator), it matters if you HAVE IT.

How do you make South Park Animations? I wanna do it!
https://www.youtube.com/watch?v=0KoI_EsV7rs - part of a bunch of animation tutorials, you can also use FlipReaperZ's tutorials.

Something else, please.
Check out these youtubers!

https://www.youtube.com/user/AlanBeckerTutorials

https://www.youtube.com/c/JesseJJones

Where to upload?
If it's swf, make sure to alert people to use a dead browser or download it and get an offline flash player - if it's DeviantArt.

If it's NewGrounds, YouTube, Vidlii, etc, use Swivel, which you can download here : https://download.cnet.com/Swivel/3000-2194_4-75863771.html (If you have GoGuardian - if not download from the official Newgrounds website : https://www.newgrounds.com/wiki/creator-resources/animation-resources/swivel-flash-to-video).

Shows (mostly web series) that use flash that are great!
Homestar Runner

Making Fiends

The Tormentor (CANCELLED, fan-made like South Park 2 Years Later)

This show (South Park 2 Years Later)

dont worry there is more.