I have been consulting the X toolkit Intrinsics and Athena Widget set documentations regularly for a while on the two hyperlinks below
https://x.org/releases/current/doc/libXt/intrinsics.pdf https://x.org/releases/current/doc/libXaw/libXaw.pdf They seem to be missing now and the website only links to old archives from The Definitive Guides to the X Window System. The disappearance of them also breaks hyperlinks at the readme on libXt's repository. If the removal was not an accident, please reconsider putting them back. There's no reason to not host them any more as there are plenty of legacy applications relying on these toolkits
