A trio of Baldwins solicitors also weighed in against the proposal.

"It is not clear why the Committee gave the open source Community submissions such weight," they write. "To argue that software is unpatentable because it builds on existing software seems unusual given nearly every invention builds on what others did before. As many innovators realise, one object of the patent system is to promote publishing of inventions. Then others have the opportunity to learn and develop from those inventions and improve our standard of living."

In response, Harrison says many members who also develop proprietary software support the exclusion and patents are harmful to all software development houses.

"The ways in which software patents can stifle innovation was given specific treatment in our submission. Our first example was a comparison to books which no doubt can be creative and innovative, but are not covered in patent law. Software is a form of creative expression in almost every way analogous to writing a book. Our second example was a description of how patents have been used to reinforce monopolies and protect the revenue streams of large multinationals, but have failed to provide revenue to New Zealand software companies," he writes.

On the divergence from Australia, Harrison points out that Europe has taken the same stance as New Zealand.