Bilibili (stylized bilibili), nicknamed B Site ("B 站"), is a video sharing website based in Shanghai, themed around animation, comics, and games (ACG), where users can submit, view and add overlaid commentary on videos. Bilibili uses Adobe Flash or HTML5 player, to play user submitted videos hosted by either itself or third-party sources, featuring a scrolling danmu ("bullet curtain," 弹幕) commenting system. Since the mid-2010s, Bilibili began to expand to a broader audience from its original niche market that focused on animation and games, and it has become one of the major Chinese video on demand over-the-top streaming platforms that programs critically acclaimed and popular documentaries, variety shows, and other original programming.