Be careful if you decide to make software to sell, if you do it at work and use your work machines then they may own it - depends on your jurisdiction / work contract. Even if you do work for others while at work then you could be in a difficult situation contractually.
Of course if you're bosses are happy for you to do other stuff just get it in writing.
Of course if you're bosses are happy for you to do other stuff just get it in writing.
obligatory not a lawyer etc.