Almost everyone should build their own framework on top of existing frameworks for their own domain. At work, we have a common look and feel for all our applic

Almost everyone should build their own framework on top of existing frameworks for their own domain. At work, we have a common look and feel for all our applications so that's build into the framework. We have specific domain specific data types -- those would never go into someone else's generic framework but they are in ours. I find this idea of building your own framework to be pretty rare -- I do it because I've actually had to build frameworks for platforms that didn't have them -- but most programmers are content to use what they're given but never think of extending it.