The variable holds the current version number of the perl/Tk
release in the form major.minor. Major and
minor are integers.
The major version number shows on which
Tcl/Tk release perl/Tk is based. E.g., 402 means based on
Tcls Tk 4.2. (Patchlevel of Tcls Tk are not incorporated because
perl/Tk tended to be ``ahead'' of them on some fixes and behind on
others. The first digest of the major version number increases in
any Tk release that includes changes that are not backward compatible
(i.e. whenever existing perl/Tk applications and scripts may have to change to
work with the new release).
The minor version depends on perl/Tk only. It uses the
'even'='stable', 'odd'='experimental' scheme that linux uses:
.0xx - inherently 'alpha'
.1xx - experimental 'beta'
.2xx - stable
.3xx - experimental
.4xx - stable
...
The minor version number increases with
each new release of Tk, except that it resets to zero whenever the
major version number changes.