Is it possible to create applications “crowdfunding web” with “scriptcase”?
Both for the “backend” and “frontend” application
Maybe there are already experienced to make it?
Yes. You can make your own applications and deploy them.
Scriptcase is NOT a CMS, but an application platform. That being said, you can integrate Scriptcase applications in your CMS using wrapper plugins, iframes and other technology. I would not recommend building your cms part in scriptcase as that is not what SC is meant for and - in fact - not good for that purpose. But to register people, interface with payment gateways etc. it works very well and you can build almost anything you like. As you ar ealready a member since 2011 you know that.
SC is not suited to work with any CMS systems and integration is a pain. Mostly because it does not follow standards which keep HTML,CSS,PHP separately. Building CMS from scratch using SC would be like reinventing the car and building all parts from nothing.