Online Program Collections

[juverax]

https://codedead.com/software All are free, several have a portable version, some have a Softpedia entry, some are open source
https://www.horstmuc.de/index.html
http://www.joeware.net/freetools/index.htm
https://www.donationcoder.com/
https://elefantsoftware-en.weebly.com/download.html All free many (maybe all) portable

[juverax]

https://www.carifred.com/ "Carifred - IT software for Windows"
Several tools are freeware, ... others are payware.
Most of these tools are oriented toward system rescue, security, Windows system administration.
Some of these tools have a Softpedia page.

https://www.mediahuman.com/products7.html
(Download page: https://www.mediahuman.com/download3.html )
Mostly utilities for finding and processing multimedia content on the web.

https://luethje.eu/prog/ Freeware
Utilities for working with accented characters and related tools
Most tools are portable (zip files)

[juverax]

Freeware developed by Jochanan Agam: https://freeware.persoft.ch/freeware_en.htm

List and download links: https://freeware.persoft.ch/program_en.htm