Facebook's "React" library was discussed here (with 100+ comments) when it launched in 2013[0]. I remember because I wrote an example to compare React with Angular, and my post was also #1 on the same day[1] :)

[0] https://news.ycombinator.com/item?id=5789055

[1] https://news.ycombinator.com/item?id=5790799