To install and run Sweet Home 2D with Java Web Start, install Java and click on this link (Sweet Home 3D and Sweet Home 2D may be installed on the same computer if needed). You may also run Sweet Home 2D by downloading the Jar executable version of Sweet Home 3D and executing the java -Dcom.eteks.sweethome3d.no3D=true -jar path/to/SweetHome3D-5.4.jar command.