I used to put both libraries in CATALINA_HOME, as past experiences made me suspect of memory leaks if any of these 2 dependencies was in each application's classpath.
However, the most recent c3p0 version has a dependency to mchange-commons-java-0.2.11.jar (which also needs to be in CATALINA_HOME), which made me re-think if that is the most appropriate location. I added more contextual information (namely, c3p0's configuration in spring) to https://stackoverflow.com/questions/45621073/where-to-put-c3p0-dependency-in-tomcat-container Could you share your experience in defining the location of these two dependencies? Thank you! Miguel