python is the programming language of choice.
The second hyperlink target (line beginning with "__") is both an indirect hyperlink target (indirectly pointing to Python website via "python_" reference) and an anonymous hyperlink target. A double-underscore suffix is used to indicate a anonymous hyperlink reference. In an anonymous hyperlink target, the reference text is not repeated. This is very handy for references with long text or throw-away references, but the target should be kept close to the reference to prevent them going out of sync.