It's more of a philosophical question than an ethical one, really; one that has been debated many times before, but is still just as important today.

Suppose, for example, you come up with a system to completely eliminate spam. Now, you can either

a) get a patent on it, and/or sell it for a huge amount of money to a big company, and become a billionaire overnight. There's nothing wrong with this, since it was, after all, your idea

b) make it open source, so that it will benefit billions of people, but you won't get a cent out of it.

Which way would you go? There's plenty of stuff still left to invent, but it seems that you can either have a big heart or big bank account, but never both.

c) Get money from spam companies to not publish your code

Interesting question. Options A and C make one wealthy. A lot of good can be done with money -- if it's in the right hands. There are many worthy organizations that rely on donations to operate.

Nevertheless: information wants to be free, and option B is of noble intent.

In conclusion, I dunno.

I vote A, because in my observation, most people prefer to use commercial software (paid for or pirated) even if the free, open-source alternative is superior.

You couldn't get a patent on it, as India is one of the good guys: no software patents. Neither could I, but I'd still make it open source even if I lived in the USA. Virtue may be its own reward, but think of the reputation you'd have and what that would do to your employment prospects. I've yet to see a beggar with a placard "FOSS developer — please give generously"!

Option A generally doesn't exist. Patent law was always partly corrupt and has evolved into totally corrupt. Patents do not provide a means for those with true innovations to protect those. Patents are only a means for those who can afford good lawyers to interfere with competition. There is virtually zero difference in the effectiveness of a valid patent for a real innovation and the effectiveness of a bogus patent that turns prior art and obviousness into something a non engineer can't tell from the real thing. Without good expensive lawyers, either kind of patent is worthless. With the lawyers, either kind of patent is a very expensive crap shoot. Either side can win and merits are never a factor.

True, I can't get a patent here for now... maybe by the time my spam system is ready, things might be a bit different

There're plenty of other things you'd get patents for - big pharmaceutical companies do it all the time, and in their case the question actually becomes an ethical one - on one hand they'll have complete monopoly over drugs that only they can make, selling for $50 what took them $2.50 to make, and on the other hand, people die because they have no money to pay for it.

Patent or no patent, the question might just be that of open vs. closed source, or copyright, for that matter. There are severe bottlenecks in various areas of progress, because some people chose to make a profit; can we call them selfish to benefit from their lifetime of research and hard work? It is most certainly a complicated question.

Hey, you know I completely agree. You need money to pay lawyers to be able to defend your patent. Looking at some historical examples you can see that some poor guy may have invented it, but some rich guy made all the money and poor guy stayed poor, and the rich guy got richer.

Really, I guess this is the reason for why the world is the way it is ...

If you release it open source you will still become famous, like Linus T, RMS, etc. Maybe you can set up an foundation for yourself, get donations, continue maintaining the solution to spam, etc.