A canary deployment is a deployment strategy that involves deploying a new version of an application alongside the stable version, directing a small percentage of traffic to the new version. This allows you to test and validate the new version before gradually rolling it out to all users. 

A canary release is an early build of an application. Splitting stable and development branches is a widespread strategy in the open-source world. Many projects use an odd/even numbering scheme to separate stable from the non-stable version.

Often companies publish canary versions of their products, hoping that tech-savvy or power users want to download and try them out. Examples of companies canarying their applications are Mozilla and their nightly and beta versions of Firefox, and Google, with its canary release channel for Chrome.