I am slowly becoming a huge convert to open-source software. I have always agreed with many of the principles of the open-source movement. But I recently started using the Scarab bug tracking system which is built on top of the Turbine framework and the Velocity templating system. The software uses Ant to build and configure the application server, framework and database schemas. These tools are incredibly valuable.
Good Development Methodology
Because these projects are built by a separated development/project team they require effective use of software development tools. Every developer, designer, project manager, and usability specialist should understand the process used to build creative, bug-free software. A good starting point is reading Rapid Development: Taming Wild Software Schedules and Code Complete: A Practical Handbook of Software Construction. These books are a great summary of the project management and development methodologies that have proven effective on a number of large scale software deployments. The open-source movement seems to practice many of these methods and build tools to help automate the best practices. Frameworks like Struts and Turbine follow the Model-View-Controller design pattern. The use of design patterns and the development of coding tools seems to have blossomed recently as part of the open-source movement. The tools feel like they have reached a point where they have been refined enough to be useful without having to do much of the development yourself just to use them.