LibreOffice Writer is capable of opening and accurately displaying AppleWorks documents, but does not indicate as such until you do it manually.
I just added support in shared-mime-info for an "Appleworks document" MIME type (https://gitlab.freedesktop.org/xdg/shared-mime-info/commit/5c9e37f85de684f7fac707531e2950e68061a64d) so it should be possible to make LibreOffice indicate itself as an app that can open documents with the new application/x-appleworks-document MIME type.
Steps to Reproduce:
1. Double-click on a .cwk document
The OS dialog for "choose an app to open this document" appears, because nothing is registered as a handler for AppleWorks documents
LibreOffice writer opens and displays the document
User Profile Reset: Yes
OpenGL enabled: Yes
Note that this is about AppleWorks documents, not iWork documents. AppleWorks was Apple's office suite prior to iWork. It was a re-branding/fork of ClarisWorks (hence inheriting the .cwk filename extension).
Reproduced with attachment 111839 [details] from bug 88098