I really like using Smalltalk (Squeak) for personal programming and small projects. It's very reflective and it is easy once you know the tools to learn more about how the system works and how to do stuff. I have not found any similar systems anywhere. I can inspect and browse the source code for the whole system and I really enjoy it. These functions are opposite of what most other systems let you do. They want to be an app like entity that fills a function without you either wanting to know how it works or being able to know how it works.