Your own framework

Your own framework that is gonna solve all the problems. It is going to be faster, easier to understand, more robust and lightweight.

There is one problem; it takes time. Probably about 3 major releases to get it right. And guess what happened after 3 years of hard work? A new technology has arisen making the existing technologies obsolete.

Take Lucene - i've been told a very elegant framework. There is new major v5 on the horizon to get everything right. Problem however is that frameworks like GWT and J2S solve a core problem; easy way of writing client side code.

Lesson: as a company don't write your own frameworks unless it is core business. Even then take into account that it is going to be out-dated in 5 years.