While I don't actually use any of those listed, I did have an Xcode link (not the one listed here) that was also broken.
As you suggest, https://developer.apple.com/technologies/tools/ does appear to be the correct (current) link for Xcode.
What I do use (almost universally) is vim.
I checked for this in Code Editors and Development Environments.
The VIM link to http://www.vim.org/ seems fine; although, I'm unsure why it's in uppercase.
However, the Perl and VIM link to http://www.vim.org/htmldoc/if_perl.html looks like a dud: it works OK but takes you to a page with <title>Vim documentation : vim online</title> and absolutely nothing about Perl at all (in fact, the only match for /perl/i is if_perl.html in the address bar).
I have http://www.vim.org/docs.php bookmarked: it has the same <title>.
Perhaps this would be a better option.
I did a search for 'perl' on vim.org: it came back with ~200 results - I didn't investigate further.