I've been thinking about writing blog posts on DevDocs's internals and the techniques it uses for a while, but it's hard to find the time, especially when I already spend a lot of my spare time maintaining/updating the app.
That said, feel free to open a GitHub issue to remind me to write blog posts at some point (if there is interest), or if you have specific questions.
Don't feel like you have to donate, though. The app is cheap to host (one of the benefits of an offline-enabled, no-accounts-required, optimized-to-the-max web app is that the backend doesn't do much :P), and I'm lucky that MaxCDN & others are providing free service to the app.
What keeps me going is seeing the impact that DevDocs is having (people using and liking it). So the best way to "give back" is to spread the word, send a thank you note, and contribute (one thing in particular that would be great to see is more/better extensions & integrations with code editors).
This software and related documentation are provided under a license agreement containing restrictions on use and disclosure and are protected by intellectual property laws. Except as expressly permitted in your license agreement or allowed by law, you may not use, copy, reproduce, translate, broadcast, modify, license, transmit, distribute, exhibit, perform, publish, or display any part, in any form, or by any means.
DevDocs is just a hobby of mine and I don't want to waste my time on a documentation that I may have to remove. If Oracle is willing to grant DevDocs a license (I haven't asked them) I'd gladly add the JDK docs to it.
Happy our paths crossed again here!