Great! :) http://rubyweekly.com/ is the Ruby one and http://statuscode.org/ is the one for programmers generally (covers algorithms, general advances in the field, generic tools, language agnostic articles, etc.)
Signed up! I don't use Ruby much, but I'm curious to see what I can steal from Ruby back to Perl. :)
BTW, you should include links to the other 3 lists on all the websites. I see that statuscode.org and rubyweekly.com have it now, but when I checked the JS site earlier I couldn't find a link.
Technically they're at https://cooperpress.com/ but the whole idea of them collecting together as related newsletters hasn't quite gelled yet. It will take a little bit of work to do it right.
BTW, there's a Perl Weekly as well which was inspired by the Ruby one. I don't run it but it's at http://perlweekly.com/ and follows a similar formula to mine.
This is a massively late reply, but I've been signed up for the perl weekly newsletter from its inception. Thank you for mentioning it though! I'm sure Gabor is grateful for the link. :)