The document discusses best practices for developing enterprise software using PHP. It recommends using frameworks to provide structure, conventions, testing and other supporting functionality. Rolling your own framework is not advised. Frameworks should be chosen carefully based on their age, flexibility and ability to integrate. The document also stresses the importance of code conventions, version control, bug tracking, formal design/specs, security practices, separating concerns, and hiring a team with the right mix of skills like programming, testing and design. Lessons learned include properly scoping the project, educating all team members, prioritizing testers, valuing designers, and accepting that software takes a long time to develop properly.