Do you discuss your startup with your current employer?

Why would you discuss it with your boss? What benefit would you expect to get?

It depends on whom you are working for. If you work for a boss that has successfully started his own company, and he fosters that type of spirit, then you may approach him as a mentor, or at least for advice, but, I would think that it will create more problems than you will gain from doing it, as it could take a while to start your business and you don't want to jeopardize your current job.

If you haven't started yet, you should talk to them first. Here's an article discussing it.

If you've already started, in my opinion the best policy is still to be up-front with it, but since you're already operating in secret it might be best to stay that way.

Bottom line comes down to your employement agreement. Most (try to) prevent you from doing such things. The legality of that is questionable, but that doesn't matter because if they sue you and lose it's still a ton of money and time for you to defend yourself. Yes of course I know people where exactly this happened.

Generally if you have to do something in secret it's because you know it's wrong.

If you are working for an employer that will treat you badly because you are starting your own company, then it is a good thing you are leaving.

If the employer will make you sign stuff, then that's a good sign, since those papers also limit him (The most important one: He cannot claim later he was unaware of your venture). You do not want to have the employer argue that the start up is really his because you (allegedly) created that on company time. You want to limit the possibility of that argument being made.

A true can of worms is opened when you start up your own company and then your old company sues you after you have left, potentially claiming ownership of your new company's assets (source code, intellectual property, etc...).

What you lose is just part of the cost of starting your own company. I have noticed that the smaller the company you work for, the larger the consequences, intentional or subconscious (your boss treats you bad or does not take you into consideration after he/she learns of your intention to start a new company).

As to how to limit the possibilities of being sued later, make sure you keep everything separate. Everything. Do not use your employer's equipment for ANYTHING regarding your new company. Above all: Do not use your time at the job for anything to do with your new company. Give back the company laptop. Give back the cellphone if you have one. Anything that might let your employer claim that you used his resources to start your company.

No. Not really.

Generally, they know I have this side "hobby", and I may talk about it as a hobby.

But work is work, family is family, and what I do in my spare time is a separate thing.

Its great if you get time to work on your own idea along with working for someone else full time. I don't think it is a bad idea to discuss your venture with your boss unless you are compromising on the work at his place. If you kick some solid ass at work and have an idea which needs some mentoring, most would show you two thumbs up! My say, don't compromise on your full time job, work hard to get your thing started (N I know its easy to say than to do it.. ), and be open about discussing it with the people you think may be helpful in some way.

My co-founder and I were obligated to discuss our start-up idea with our employer, according the terms of our employee agreement.

We would have been delighted if the head of product development said, "That's an awesome idea, we'll do it." (We were primarily interested in solving a problem, not running a business.)

That was the opposite of what he said, though. The gist of his response was that it was a really creative idea, but the old company wasn't interested, and could we please just get back to work now.

Ultimately, this was great for us. We'd done our duty to bring the idea to our employer, and we had (in writing) their decision to pass on it. We could then quit and do our own thing without any legal entanglements whatsoever.