IPW is freely distributable. Much of the source code is in the public domain; the remainder is copyrighted but is freely distributable. This is obviously important to academic users with their chronic shortage of funds. However, the main reason IPW is freely available is to maximize its utility as a tool. IPW users may become IPW programmers if they wish, since they will always have access to the source code. Bugs are more likely to be uncovered (and fixed) if the person encountering the bug can debug the program at the source level. Most important of all, IPW is more likely to be extended if its source code is available for study and emulation.
To address this goal in IPW Version 2, all the supporting software packages required for IPW (e.g., Perl and GNU's make) were limited to those which are also freely distributable. To see what software packages IPW currently requires, please consult the System Requirements.