IMPORTANT: As of February, 2017, the Crosswalk Project has been retired. Crosswalk 23 was the last version of the Crosswalk library produced by the Crosswalk team. You can continue to build for the Crosswalk library using Cordova CLI or PhoneGap Build, but no further updates to the Crosswalk library will occur beyond version 23 (FYI: the Crosswalk 23 library for Android is based on the Chromium 53 runtime release).
A future version of this page will be updated with instructions regarding how to transition your mobile app away from using Crosswalk. Until that has been written, please see this forum post for some help with that transition.