Custom .Net application on SharePoint

Following are the few points I would suggest considering when deciding whether to use MOSS as the platform for the application you develop.

1) Is your application centered on Documents?
2) Is your application looking for collaboration features like blog, Wiki, Tasks etc?
3) Is your application about managing the web content and require content authoring, review process to publish the content to web?
4) Is your application looking at managing a unstructured content?
5) Is your application looking managing site strcture (Site-->sub site)?
6) Is your application looking at using Out-of-the Box User Management, Access Control?

If your answer is yes to any of the above questions then you can consider SharePoint.


Also MOSS is not a recommended plaform if you are looking at building
1) Transaction based application which would require use of a Custom database
2) Application as a Front end that leverages all of it features through external systems and nothing from MOSS features