Most of the web applications these days have some standard components such as user registration, login, signout, updating profile etc. If you add saas into the mix, that would include billing, membership tiers etc. It would be nice if these are available as part of a starter kit, so a developer can focus on the core app. This helps a lot in developing prototypes fast and a bit more complete.<p>So, do you know any good web application starter kit that includes some of the above features? It could be in any language.
Web2py (Python) provides a lot of that functionality so you can dive right in on your app. It includes all of the user account stuff but not the payment processing. It also provides a complete admin function. The only caveat, if you care about such things, is that many Pythonistas don't like some of the non-standard approaches Web2py takes. But I have found it extremely easy to use to quickly create apps.
Many web frameworks have these basic building blocks. I'm a PHP guy, so I'd recommend the standard options: Zend, CakePHP, CodeIgniter, etc. They will all do registration, login, profiles, etc., as well as get you security features and a platform for plugins developed by third parties.<p>Many of them have plugins for payment stuff as well.