Sad news, and I frown upon the reasons for its going away. From the announcement:

In recent years maintenance has become a burden. Most of the site is running 2005 era Perl code.

As if old code would rot away. And below in the comments, this (emphasis mine):

Nigel HorneMay 17, 2018 at 1:00 PM

That's a shame. I prefer the clean interface of search.cpan.org over the metacpan site.

Where's the source code? May be kinda fun to play around with.

DanMay 17, 2018 at 1:29 PM

https://github.com/metacpan/metacpan-web for the interface, https://github.com/metacpan/metacpan-api for the search/index backend


DanMay 17, 2018 at 1:37 PM

If you meant the source code of cpansearch, it has never been published.

Wait, what? It has never been published? And then maintenance becomes a burden? Whilst I am deeply thankful for Graham for having it written in the first place, and all maintainers who helped to keep it running, I have to say:

Congrats, search.cpan.org maintainers for not leveraging support from the community which this wonderful tool helped to build.

Perl itself is in git for a long time now. Why didn't that happen with the code for that site?