Gwtar: A static efficient single-file HTML format
It appears that you haven't provided the content of the article, just the URLs. Based on the URLs, the article seems to be about "GWTAR" from the website gwern.net, and there's a discussion about it on Hacker News (news.ycombinator.com) with 239 points and 76 comments. To provide a proper summary for your newsletter, could you please provide more context or information about what GWTAR is and what the article discusses? Alternatively, I can try to look up the article and provide a brief summary if you'd like.