The default output logger text has now colored output if the output terminal supports it.
The -F option no longer suppresses normal output. The old behaviour can be restored by giving the option -onone.
The --status option is now the default and has been deprecated. The old behaviour can be restored by giving the option --no-status.
The default recursion depth is now infinite. The old behaviour can be restored by giving the option --recursion-level=1.
The option --strict has been renamed to --extern-strict-all.
The commandline program linkchecker returns now non-zero exit value when errors were encountered. Previous versions always return a zero exit value. For scripts to ignore exit values and therefore restore the old behaviour you can append a || true at the end of the command.