The Reseller API is built on HTTP and JSON, so any standard web stack can send requests to it and parse the responses.
However, instead of creating HTTP requests and parsing responses manually, you might want to use the Google APIs Client Libraries. The client libraries provide better language integration, improved security, and support for making calls that require user authorization.
In the following tables, the first column shows each library's stage of development (note that some are in early stages), and links to documentation for the library. The second column links to available samples for each library.
These early-stage libraries are also available: