I’m wondering if this platform is solely used for games dev/sale or it’s possible to sell other types of programming peoducts here
https://itch.io/docs/creators/faq#what-limits-apply-to-projects-and-accounts
Because itch.io lets users download the files exactly as you uploaded them you can upload any kind of project for any kind of platform. There are no restrictions.
We have classifications for tools, comics, books, soundtracks, assets, and physical games. If that’s not enough, you can even customize the noun by which itch.io refers to your project.
As pointed out above, there are still restrictions, but those are the usual legal restrictions like having rights to sell or publish the thing.
You will even find some videos. And misleadingly named physical games. It still is a document/rule book you download, not physical merch.
For source code you sell, you should be clear about what people buy and what licenses apply and if those licenses are ok for selling.