I wonder, what options do I have in the following situation. In the course of the several projects I realised the need in some auxilary software product (related to testing of the main products). I applied a creative approach to the matter and implemented a system which I think has a potential and looking promising (maybe not on the market but at least among some interested supporters). I have even more ideas related to this system and continue developing at my free and work time. It has become a work and hobby at the same time.

Unfortunately, this work basically has nothing in common with the company's business and there is no way this will be organized in a form of standard development process and be presented to costumers as a product.

What can you suggest in this situation? How to avoid breaching of contract? Have you had something similar in your career? What if my intention is to develop it as an open source project?