The reason I'm asking is this: I currently run a sole proprietorship. I plan to establish a Limited company in 6 months time. The Limited company will take ownership of all software I produce in the meantime. If I write code NOW that infringes on copyrights or violate patents, and the Limited company gets sued for it in 12 months from now, who is responsible? Who takes the hit?
PS: I do of course not intend to infringe on patents, I just want to pinpoint my risks .
PPS: Norwegian law applies, but I guess they will mirror US or UK laws in this case.
I will answer the question from the perspective of law in the U.S.
The appropriate practice is for a founder to assign assets, including intellectual property rights therein, to his corporation pursuant to a written agreement. That agreement should state which party is responsible for any claims alleging infringement of intellectual property rights. In my experience, most founders would want corporate, rather than personal, responsibility - after all, that is a major reason why the corporation was formed.
Accordingly, the answer to your question is: It depends on what the assignment agreement says.
Disclaimer: This information does not constitute legal advice and does not establish an attorney-client relationship.
If I understood correctly, you are worried about your personal risk. And you shouldn't be. From legal point of view the subject that is being sued takes potential hit. In this case it can only be company as company will be he one that makes profits from potentialy patent infringing software.
But in software industry, generally you shouldn't be too worried about patent infringing, especialy if you are a start-up. There are noumerous of reasons why patent owners (usualy large corporations) don't sue small start-ups.
I suggest you to read this essay on software patents which I found very well and reasonable written. It's about reasons why examples when one big corporation sues smaller company are rather rare and in general provides realistic view on software patents related issues.