- Mixing open source and commercial tools can provide benefits but also risks that require careful integration. A case study describes blending open source and commercial testing tools for a Java application. Subversion, JIRA, Eclipse, IBM Rational Functional Tester, and Maveryx were combined in the test environment. The strategy was to reuse tests developed in Rational Functional Tester for legacy functionality and develop new tests for new features using Maveryx.