I'm given the choice to learn and become a C#/.Net developer with a company that is now shifting towards that. Or do I keep on doing Ruby and go with a company I recently got an offer with. The only reason why I'm thinking about leaving my current company is because they are going back towards .Net besides staying with open source. Some things that I'm afraid of are C# devs seem to have more shelf life and program more in their later years than Ruby devs. Also I'm concerned about the future of Ruby. I know that I have to learn another language but I would prefer to stick with Unix or Linux besides programming with Visual Studio/Windows.