They've been spamming /r/web_design and Hacker News for a few weeks now. For example check out this new guy's only submissions and comment:

https://news.ycombinator.com/user?id=browserspot

Here's some more (all new accounts besides the first submission which I assume is a dev of this CodePen rip-off):

https://www.hnsearch.com/search#request/all&q=liveweave.com&start=0

Some of the comments by those accounts are ridiculously fake:

https://news.ycombinator.com/item?id=6525760

2 out of 8 of this guys comments are BS replies to the spammed Liveweave links:

https://news.ycombinator.com/threads?id=filipedeschamps

And the other 6 are very short comments with no thought put into them (obviously to throw off the spam filter).

As I mentioned before, this is also going on in reddit.com/r/web_design. New accounts keep posting these links that get to the front page more than they should. I wouldn't be surprised if the person behind Liveweave was actually paying someone else to make these CSS/JavaScript demos.