Totally different. Darkstar was build from the ground up for game transactions. Very different set of requirements and needs from a development perspective.
Glassfish is a set of modules bundled together into an distribution. v2 had its own module system (based on HK2), v3 will use OSGI. There are no technical reasons why darkstar is a separated project and lives in a separated community. The smallest subset (worst case, which means started from scratch like it is now) which could be reused from glassfish are monitoring, admin and module system.
well a platform usually manages common tasks like modularity, window management, configuration, wizards etc. (aka the app server for desktop apps). A minimum eclipse RCP or NetBeans apps is a empty gray window...
and are also loud, create dependency, and force you to dowload several Mb to produce a simple window
again, platforms are modular and solve common tasks you would have to implement in a large project anyway. I think you are confusing IDEs with application platforms (e.g eclipse RCP, or NetBeans platform). The main point is that applications like an designer are no "simple window" and people already realized it.
Modular means you can extract everything useful and remove everything you won't need or you want to improve because of
for example special "design and interaction needs". You have no dependency to the platform, just to the module you like to use and the module system. In fact I know even a project which uses NetBeans filesystem apis in a non desktop application.
NetBeans uses a default Java services lookup mechanism (but a little bit extended), eclipse OSGI for modules and is the standard in most enterprise systems.
It is extremely inefficient to solve already solved problems. At least in germany it would be really hard to convince people to pay for a middle sized desktop project which is not based on a platform.