I told my boss I had an idea for a program that could improve efficiency across much of the business, and he let me build it on company time. In the long term, he wanted to be able to sell it to other companies. However, the program never got implemented due to personnel mismanagement, and I’d rather be able to post it on my github under a free licence so I can use it as a resume item, and at least someone would have the chance to actually use it. It’s all still in my head, and I could write it again if I wanted. If I do, is it illegal to publish it? What if I write it in a different language? Do I need to change the variable names? I did plenty of research and planning on company time to build it, and it’s not like I can research it again, it’s all still in my head.
Not a lawyer, but worked closely with them in the past. It REALLY depends on your employment contract. Changing variable names and language still makes it a derivative work, so it would depend on the original license. I’m assuming it doesn’t have a license which would mean either you or the company owns the copyright: depends on your employment contract. Whether you’re a contractor or full time also affects ownership.
Without ownership or a license, you do not have the legal right to copy the work or make a derivative of it.
I’m not clear on whether you actually wrote any code though. If that’s the case (that no code was written) then I’m not really sure how that works out. If you do post it and they find out, AND they’re mad about it, you could definitely get fired. I’m not sure if there could also be legal trouble or not.
If you need it for a resume item, you can just list it on your resume and talk about it. You could also implement it on your own time (but not share it until you’re sure you’re safe from legal action), that way you could talk about tradeoffs you’ve made, etc. in the real implementation.
In general, if you’re not sure and you’re worried about getting sued, you should ask a lawyer.