1)You get thru downloading the thing since it advertises support for your printer, 2)Click on it to start using it right? 3)Right? 4)X out of the login window because you don't have a login and don't want one thanks. 5) Put the newly downloaded file in the trash bin. 6) Right click on the trash bin and "empty trash" 7-10) Relax for a bit since you don't have yet another data collecting app spying on you. But then post about how shitty the experience was.
I can't believe anyone would actually create a login to use an app like this. Fuck that. I will just use shitty chitubox for now. Fuck^2, but at least I don't live in some shit server with all my 3D models stolen or my credit card or GPS or whatever the fuck they want to get from me. I'm sure chitubox is already doing it, but hey I don't need a password for that.
PrusaSlicer is a fork of Slic3r Bambu's slicer is a fork of PrusaSlicer Orca Slicer is a fork of Bambu's slicer and also pulls in ideas from super slicer (another PrusaSlicer fork).
In other words, they all share a common lineage. Each adds quality of life improvements over the fork, at least in theory. It's possible those quality of life improvements will make it back upstream to the thing that was forked.
As for specific examples, Orca Slicer has a somewhat different set of tuning parameters, some unique-to-it quality things like scarf seams, built in tuning prints (temp towers, EM multiplier, pressure advance, a test to find your max flow rate, etc) a revamped UI, etc. I haven't compared the two in a while, so it's possible that some of this has made its way upstream by now.