Dropbox has actually had Selective Sync for years.  The whole part about the metadata being cached locally and a seamless experience at file system level is new though.<p><a href="https:&#x2F;&#x2F;www.dropbox.com&#x2F;en&#x2F;help&#x2F;4456" rel="nofollow">https:&#x2F;&#x2F;www.dropbox.com&#x2F;en&#x2F;help&#x2F;4456</a>