Alpha testers and Eucalyptus developers are welcome to try out our nightly builds. But everyone else should go for the latest stable release.
The current stable release of Eucalyptus, version 2.0.3 and the current stable release of Euca2ools, version 1.3.1, can be installed from source or as binary distribution-specific packages (for RHEL, CentOS, Debian, and openSUSE). Ubuntu Lucid users can install the latest release from the standard Ubuntu supported repository, or users of any Ubuntu release from Jaunty and later can always install Eucalyptus from source. Source, dependencies, and binary packages can be downloaded as tarballs, while for packaged releases we also maintain RPM and DEB repositories (click the links below for more information on setting up your system to use the repository). You might want to skim the Administrator's Guide to understand the steps involved for installing using these different methods.
Follow the instructions in the Administrator's Guide assuming $VERSION=2.0.3:
Follow the instructions in the Euca2ools Guide assuming $VERSION=1.3.1: