This manual does not refer explicitly to any particular version of eCos. However, version numbers form part of many file path names. In all of these places the version number will be shown like this: <version>.
If you have used anonymous CVS to check eCos out of the CVS repository, the version number will always be current, since that is the name of the directory in the repository. When a stable release is made this directory name is changed, in the release, to the number of the release, for example v2_0 or v2_1.