I have <looks at search.cpan> four distributions on the CPAN with version numbers less than 1. Three I inherited from other people and have decided to keep their version numbering scheme, on the grounds that suddenly jumping from version 0.12 to version 1 would be just as misleading about the state of the software as it is to leave it alone. The fourth - Data::Transactional - is all my own work and is at version 0.1 because it has at least one documented major bug, perhaps one documented minor bug, and it solicits feedback about the internals (of which I have received none).

On the other hand, the interface is stable, it does something useful, and it passes its tests.