Namespace includes a selection of native integrations that provide deep support for a particular language/framework. Beyond image building, an integration may do other things, such as setting up file sync for Node.js development.
Integrations are modeled in an extensible way as we allow many integrations to be added over time. Let us know on Discord if you're missing a particular integration.
Beyond integrations, Namespace also supports pre-built images from an image registry. Take a look at the reference for more details about the syntax.