Today, people generally spend more time on web-apps and web pages then on the native desktop and mobile applications (web browsers excluded, of course). However, web-based applications usually don't work as fast as the native ones and that is actually becoming a problem. This is why Microsoft, Google, Mozilla and a few other less mediated companies came up with an initiative called WebAssembly. This tool will provide developers with a way to compile the source code of web-apps, so that browsers can process them a lot faster. The project is really great as it doesn't only offer a better environment for web-based productivity apps, like Docs or OpenGoo but it could also provide a more reliable solution for other things. For example, currently, creating rich browser games or online video and image editing tool is problematic, but that could all change.
At the moment, WebAssembly is still in its very early stages, so it will be a while until all the developers will be able to utilize it.