IMO - if you are starting a project as a business, go with what you or your developers are most comfortable with. If for some reason you need to change down the

IMO - if you are starting a project as a business, go with what you or your developers are most comfortable with. If for some reason you need to change down the road then so be it. There are plenty of sites that are highly successful that have been built on PHP. On the other hand, if you are building a project to learn from, or for personal reasons, then take the time to start learning a new language. This is not to say you can't invest time in another language to build a project in a different language. There may be reasons where PHP will just not cut it. So to answer your original question. There are no projects I am sorry for building in PHP. However, there are projects where I look back and say I wish I had taken the time to learn a different language. Those projects tend to fall into the second category and I was just too lazy to take the time to learn something new/different at the time.