- The developers who write it are passionate about solving the problem because its generally a problem for them.
- It requires creativity to solve a problem in the limited time available. This leads to innovative design.
- The software tends to be focused on solving one problem really well, not being all things to all men.
- With no marketing budget the software needs to speak for itself
- The developer is completely free to do things the right way not the quick way
- Pier pressure keeps coding standards way higher than you would normally expect
- It has really cool names like Git and Gimp!