If you're big enough to have to pay and big enough to own a web site, then you must put up a page telling us how you fulfilled your obligation to make this payment. Distributing unmodified software commercially To redistribute unmodified software you obtained from someone else, you must provide a means for the recipient to obtain the source code for any IPL component of the software by means at least as cheap, easy, and convenient as the means by which they purchased the binaries. You are also under a moral obligation to pay royalties to the software authors. Include your own copyright notice if you wish, because the IPL doesn't steal your copyright. It gets a little bit hairier if you do funny stuff like extracting and combining bits and pieces from various different projects, but such major reorganisations don't happen often.
Most software development consists of modifying an existing product.
The bookkeeping needed to maintain this file is about the minimum we can expect to preserve the rights of donors of free software whilst permitting commercial use. You still have an obligation to pay royalties on that proportion of the product that came from IPL source and you can't sign away the rights of the IPL authors in relation to your customers. Questions and answers General questions That licence looks vaguely like Mozilla. Version 0.02 of the IPL was made by adding to and modifying the Mozilla Public Licence by Netscape. The IPL differs substantially from the MPL and the two should not be confused.