Last updated: 8 September 2026
What this is
korczak.xyz is a personal site: a blog, a songbook, some course notes, and a set of small apps I build for myself and leave open to anyone who finds them useful. It is not a commercial service, and nothing here is for sale.
Provided as it is
The site and its apps are provided as they are, with no warranty of any kind. They may change, break or disappear without notice, and no uptime is promised.
Keep your own copies
The apps are not a backup service. Data held in your browser is gone when you clear your browser storage, and synced data can be lost too. Export or copy anything you would miss.
Accounts
The accounts on this site are mine. Please do not try to sign in to one you were not given, or to reach data through the site that was not meant for you.
Content
The writing, the code and the design here are mine unless stated otherwise. Song lyrics and chords in the songbook belong to their respective rights holders and are reproduced for personal and educational use; if you hold rights to something there and would rather it went, write to me and it goes.
Liability
So far as the law allows, I am not liable for any loss arising from using this site — lost data, a missed notification, or anything you trusted one of the apps to remember.
Contact and changes
Questions go to oskar.jan.korczak@gmail.com. These terms may change, and the date above says when they last did. Polish law applies.