Glassfish for Independent Software Vendors (ISV)
Independent software vendors have to cope with many different customer infrastructure requirements. Once you decide to support a certain combination of e.g application server and database, then you are stuck with it for quite a while. So those decisions have a big impact because you have to test, maintain and sustain a large set of components that also evolve overtime.
This ISV had a very interesting strategy. They bundled a web container with their product. This reduces the number of customer infrastructure component and it eliminates a big dependency in test and QA processes. It should not surprise you that the web container of their choice was Tomcat. According to them: if Glassfish is an alternative to Tomcat then this will allow our customers to scale way beyond the current boundries.
More information on Tomcat versus Glassfish, please read here. Or additional more technical discussion by Aran Gupta
