An online activist has proposed a tax credit for businesses and individuals engaged in the creation of open source software. Carl Malamud, the chief technology officer of Invisible Worlds Inc, has written an open letter to US Senators, Members of Congress and Vice President Al Gore outlining his idea. Malamud suggests that anyone who produces software that is in the public domain and that is used by at least 1000 people should be entitled to deduct the development and operational costs from their gross income for tax purposes. Take the example of the work of Paul Vixie, who has placed in the public domain the software that the Domain Name System runs on, Malamud writes. The software has been used by every major Internet Service Provider and has been bundled into the operating system products of IBM, DEC, Silicon Graphics and Sun. He reasons that since it was open source software that created the internet, and hence the current economic boom enjoyed by Silicon Valley, the federal government can and should take steps to provide even more fuel for the growth of the information economy.