You can download the .html file of the client to play single-player worlds without an internet connection.

Navigate to the Multiplayer menu. Popular servers like ArchMC often support multiple versions of Eaglercraft, including Bedwars and Survival game modes. Version - Eaglercraft

Includes the introduction of the Savannah, Roofed Forest, Birch Forest, and Mesa biomes.

Any modern browser like Chrome, Firefox, or Safari that supports WebGL will work.