One thing that scared us when we considered incorporating was the personal holding company rule, which can impose a 70% penalty tax on a corporation that makes too much of its money from royalties or other passive income. It turns out that there's a nice, clean exemption, designed for the use of movie and TV production companies, whose business is really very similar to the software business.
The rule is something like this: if half your income is from the
sale of copyrighted material, and you spend 15% on expenses
other than salaries, you're not a personal holding company. Our
material will certainly be copyrighted, and we'll have no trouble
spending 15% on advertising, so we seem to be home
free.