This is a conference for developers, so the announcements were pretty geeky, but the biggest deal was probably the ability for people to build apps that integrate directly into Facebook Messenger.

So, for instance, ESPN will have an app that lets you insert funny animated GIFs of sports events directly into a Messenger message.

Another big move was a video player that any site will be able to embed directly on their site, like you can do with YouTube videos today. Video has been a huge focus for Facebook recently, and this will extend its video reach to the entire web. It's a huge strike against Google's YouTube.

Facebook also announced an update to a mobile advertising product called LiveRail. It will help publishers show so-called "native" ads -- ads that integrate directly into the stream of content -- and make money from them. It's basically a big strike against Google's DoubleClick platform, which is the dominant force in online advertising.