Most companies make you sign agreements which say all IP created during employment is owned by the company. A fair number of companies allow employees to retain IP related to side projects as long as they don't directly compete with the company's products.
My company makes you preapprove any outside business activities (including freeware/opensource). They ask you stuff like if you are working in the same domain as the company, if you work with any company competitors or clients, etc.
I can't say the name because I am critical of them and need to stay employed.