I have pulled the archive of the X3 Wiki from the Wayback Machine and hosted it at http://x3.solasistim.net/. This is a strictly non-interactive version; it's no longer a Wiki, and has no editing features, and some rather demonstrably broken visuals. It mostly doesn't matter, as the content is textual. In the future, I intend to fix the most egregious errors if it turns out to be necessary.
So please visit the X3 Wiki archive.