We are spoiled by Java. For almost any programming task, you can imagine there are many freely-available, open-source projects you can choose from. If I was managing a team and they came to me suggesting that we write our own ORM framework, I would send them home and tell them to come back when they sobered up.
You may also like: Introducing Hrorm: A Simple, Declarative, Type-Checked ORM
Nevertheless, when I was working on a personal project beginning last year, I could not find what I wanted, and so I began hrorm. I've written some articles about hrorm (for example, here) that describe some aspects of hrorm. In this article, I want to talk about some of the questions I faced in writing hrorm, and why I made some of the choices I did.