Capella Studio provides a full-integrated development environment which aims at facilitating the development of extensions for Capella.
It can be downloaded on Capella project site.
It embeds several tools such as VPDSL, a textual definition helping to extends Capella core elements and generate automatically a skeleton Viewpoint with Model and Diagram extensions, Semantic Browser, Property views.
With some slight modifications, the skeleton viewpoint can be customized to create Viewpoints such as Basic Performance Viewpoint below
See also the main Kitalpha project site and the top-level wiki page.
For details about viewpoint development consult the Capella Studio documentation.