[vikingerik]

It's worth mentioning the common advice here though: do not use company time or equipment to work on a side project, since that may give them a legal claim to ownership of the work if they ever find out.

The specifics will vary greatly depending on your employment agreements and legal jurisdiction, so make your own decisions regarding your own situation (doing it on company time might be the lesser risk compared to not doing it at all), but do be wary.

[learc83]

If you’re salaried, there’s no such thing as company time, so that’s not a meaningful distinction.

[mediaman]

If you are doing it in a company office, using company property, during hours the company expects you to be working, do not expect to use "well, I'm salaried, so it doesn't matter" as a legal defense and win.

[learc83]

Company property is a completely different issue. Whether you do it during business hours or not is irrelevant.

If you’re salaried, you’re always on company time, so whether the company owns it or not is up to the laws of the state and the agreements you signed when hired.

[abnercoimbre]

What if you did most of your project outside the company, but only very small parts of it on company property? Can they still claim complete ownership?