A method and apparatus for timely delivery of classes and objects is provided. A header comprising timing information is attached to said classes and/or objects. A “start loading” time and a “load by” time are specified in the header. Other classes and/or objects to be loaded are also specified in the header. Optional compression, security, and/or error resilience schemes are also specified in the header. A process for creating the header and attaching it to a class or object is provided. A process for receiving and processing a class or object with an attached header is provided. Embodiments of the invention allow timely delivery of classes and/or objects over a wide variety of transport mechanisms, including unreliable transport mechanisms and those lacking any guarantees of timely delivery.