Select the most up-to-date Eclipse Scout release anytime you start a new project. In case you still need an older version for historical research, you can find it here.
Major Scout versions are released twice a year. The first release of a year gets updates until the second release is published. After that, the first release becomes unsupported. The second release gets LTS status (long-term support) which means critical bugs will be fixed for about 2.5 years.
The first number (major) of the version represents the year. The second number (minor) represents the release within that year. The third number (micro) is increased on every bug-fix update.