Shadowsocks is an open-source project focused on secure communication protocols. It has released several versions over the years, with the latest stable version being Shadowsocks 3..4, released on December 29, 223. This version includes several key improvements, such as enhanced security features, better authentication support, and improved performance. In comparing versions of a software or project, it's important to look for updates that include new features, bug fixes, and improvements in stability and performance. For Shadowsocks, each version builds on the previous one, adding new capabilities while refining existing ones. If you're looking for the latest version, Shadowsocks 3..4 is the current stable release, followed by .3, which was the last major release before 3..4.