Technically, Spring Insight does not need tcServer to do its job. It can work with JBoss and other containers. However, the simplest batch solution for VMware is to distribute it as a template for tc Server. VMware does not document the settings / JVM class settings necessary for Insight to work with other containers. Again this is technically possible, but not currently supported. I believe that the configuration will be supported in the near future (within a month or 2)
Since tc Server is free for developers and essentially the same as Tomcat, why can't you use it with tc Server? The integration is pretty nice (especially with STS / Eclipse)